cataclysmics, symbiotics, novae - astrosurf · eg and j. guarro 28/01/2017 3736 7448 1109 gh gem f....
TRANSCRIPT
Eruptive stars spectroscopyCataclysmics, Symbiotics, Novae
ARAS Eruptive StarsInformation Letter n° 31 #2017-01 31-01-2017
Observations of January 2017
Contents
Authors : F. Teyssier, S. Shore, P. Somogyi, D. Boyd, P. Berardi, F. Boubault, O. Garde, Vincent Lecoq
Novae
No spectra in December
Symbiotics
Ongoing campaign CH CygniAX Per in eclipseNew spectra of the newly discovered bright symbiotic SU Lyn
Nova Like
V Sge
Miscellanous New observations of the historical outburst of the blazar CTA 102, by F. Boubault & J. Guarro CI Cam
Steve’s notes
Some fluid notions and motionsSome comments about CH Cyg and SU Lyn
New publications
“We acknowledge with thanks the variable star observations from the AAVSO International Database contrib-uted by observers worldwide and used in this letter.”Kafka, S., 2015, Observations from the AAVSO International Database, http://www.aavso.org
Symbiotics in December
Observing : main targets
CH Cygni : ongoing campaign upon the request of Augustin Skopal and Margarita KarovskaAX Per : eclipse
SYMBIOTICS
ARAS Eruptive Stars Information Letter 2017-01 - p. 2
Name AD (2000) DE (2000)AG Dra 16 1 40.5 +66 48 9.5AG Peg 21 51 1.9 +12 37 29.4AX Per 01 36 22.7 +54 15 2.5BF Cyg 19 23 53.4 +29 40 25.1BX Mon 07 25 24 -03 36 00CH Cyg 19 24 33 +50 14 29.1CI Cyg 19 50 11.8 +35 41 03.2EG And 00 44 37.1 +40 40 45.7R Aqr 23 43 49.4 -15 17 04.2RS Oph 17 50 13.2 -06 42 28.4SU Lyn 06 42 55.1 +55 28 27.2T CrB 15 59 30.1 +25 55 12.6V443 Her 18 22 8.4 +23 27 20V694 Mon 07 25 51.2 -07 44 08Z And 23 33 39.5 +48 49 5.4
ARAS Data Base Symbiotics : http://www.astrosurf.com/aras/Aras_DataBase/Symbiotics.htm
Symbiotics in ARAS Data Base Update : 31-01-2017SYMBIOTICS
ARAS Eruptive Stars Information Letter 2017-01 - p. 3 ARAS Eruptive Stars Information Letter 2017-01 - p. 3
# Name AD (2000) DE (2000) Nb. of spectra First spectrum Last spectrum Days Since Last
1 EG And 0 44 37.1 40 40 45.7 68 12/08/2010 28/01/2017 62 AX Per 1 36 22.7 54 15 2.5 144 04/10/2011 28/01/2017 63 V471 Per 1 58 49.7 52 53 48.4 6 06/08/2013 18/12/2016 474 Omi Cet 2 19 20.7 -2 58 39.5 10 28/11/2015 14/01/2017 205 BD Cam 3 42 9.3 63 13 0.5 25 08/11/2011 28/01/2017 66 UV Aur 5 21 48.8 32 30 43.1 49 24/02/2011 28/01/2017 67 V1261 Ori 5 22 18.6 -8 39 58 7 22/10/2011 29/10/2016 978 StHA 55 5 46 42 6 43 48 2 17/01/2016 25/01/2016 3759 SU Lyn 06 42 55.1 +55 28 27.2 5 02/05/2016 21/01/2017 13
10 ZZ CMi 7 24 13.9 8 53 51.7 35 29/09/2011 28/01/2017 611 BX Mon 7 25 24 -3 36 0 40 04/04/2011 21/01/2017 1312 V694 Mon 7 25 51.2 -7 44 8 178 03/03/2011 22/01/2017 1213 NQ Gem 7 31 54.5 24 30 12.5 47 01/04/2013 25/01/2017 914 GH Gem 7 4 4.9 12 2 12 4 10/03/2016 07/01/2017 2715 CQ Dra 12 30 06 69 12 04 8 11/06/2015 09/07/2016 20916 TX CVn 12 44 42 36 45 50.6 33 10/04/2011 21/01/2017 1317 IV Vir 14 16 34.3 -21 45 50 3 28/02/2015 20/06/2016 22818 T CrB 15 59 30.1 25 55 12.6 155 01/04/2012 21/01/2017 1319 AG Dra 16 1 40.5 66 48 9.5 168 03/04/2013 21/01/2017 1320 V503 Her 17 36 46 23 18 18 2 05/06/2013 13/08/2016 17421 RS Oph 17 50 13.2 -6 42 28.4 33 23/03/2011 01/09/2016 15522 V934 Her 17 6 34.5 23 58 18.5 19 09/08/2013 14/08/2016 17323 AS 270 18 05 33.7 -20 20 38 2 01/08/2013 02/08/2013 128124 YY Her 18 14 34.3 20 59 20 19 25/05/2011 15/07/2016 20325 FG Ser 18 15 6.2 0 18 57.6 3 26/06/2012 24/07/2014 92526 StHa 149 18 18 55.9 27 26 12 3 05/08/2013 14/10/2015 47827 V443 Her 18 22 8.4 23 27 20 33 18/05/2011 08/09/2016 14828 FN Sgr 18 53 52.9 -18 59 42 4 10/08/2013 02/07/2014 94729 BF Cyg 19 23 53.4 29 40 25.1 101 01/05/2011 30/11/2016 6530 CH Cyg 19 24 33 50 14 29.1 428 21/04/2011 21/01/2017 1331 V919 Sgr 19 3 46 -16 59 53.9 2 10/08/2013 10/08/2013 127332 V1413 Aql 19 3 51.6 16 28 31.7 6 10/08/2013 31/10/2016 9533 V335 Vul 19 23 14 +24 27 39.7 7 14/08/2016 31/10/2016 9534 HM Sge 19 41 57.1 16 44 39.9 9 20/07/2013 26/08/2016 16135 QW Sge 19 45 49.6 18 36 50 7 14/08/2016 31/10/2016 9536 CI Cyg 19 50 11.8 35 41 3.2 133 25/08/2010 30/11/2016 6537 StHa 169 19 51 28.9 46 23 6 2 12/05/2016 14/05/2016 26538 V1016 Cyg 19 57 4.9 39 49 33.9 12 15/04/2015 01/12/2016 6439 PU Vul 20 21 12 21 34 41.9 12 20/07/2013 06/10/2016 12040 LT Del 20 35 57.3 20 11 34 1 28/11/2015 28/11/2015 43341 ER Del 20 42 46.4 8 40 56.4 5 02/09/2011 31/08/2016 15642 V1329 Cyg 20 51 1.1 35 34 51.2 8 08/08/2015 26/12/2016 3943 V407 Cyg 21 2 13 45 46 30 12 14/03/2010 18/04/2010 044 StHa 190 21 41 44.8 2 43 54.4 17 31/08/2011 30/10/2016 9645 AG Peg 21 51 1.9 12 37 29.4 200 06/12/2009 25/01/2017 946 V627 Cas 22 57 41.2 58 49 14.9 18 06/08/2013 20/01/2017 1447 Z And 23 33 39.5 48 49 5.4 77 30/10/2010 26/01/2017 8
Symbiotics observed in January, 2017SYMBIOTICS
Object Observer Date Resolution
AG Dra D. Boyd 13/01/2017 3901 7380 740AG Dra P. Somogyi 21/01/2017 4232 7193 730AG Peg F. Teyssier 02/01/2017 4207 7162 11000AG Peg D. Boyd 19/01/2017 3901 7380 729AG Peg F. Boubault 25/01/2017 4002 7501 2200AXPer D. Boyd 05/01/2017 3900 7380 721AXPer J. Guarro 42741 3724 7473 700AXPer P. Somogyi 08/01/2017 4186 7138 561AXPer D. Boyd 09/01/2017 3901 7380 714AXPer J. Guarro 12/01/2017 3788 7448 1062AXPer F. Teyssier 18/01/2017 4207 7162 11000AXPer D. Boyd 20/01/2017 3901 7380 719AXPer P. Somogyi 20/01/2017 4231 7175 709AXPer F. Boubault 21/01/2017 4001 7500 2200AXPer P. Somogyi 21/01/2017 4223 7183 685AXPer P. Somogyi 22/01/2017 4243 7205 738AXPer P. Berardi 26/01/2017 6326 6796 5547AXPer J. Guarro 28/01/2017 3749 7448 1088AXPer D. Boyd 28/01/2017 3901 7380 736BD Cam J. Guarro 12/01/2017 3715 7448 1082BD Cam O. Garde 20/01/2017 4186 7314 7BD Cam F. Boubault 25/01/2017 3950 7502 2200BD Cam J. Guarro 28/01/2017 3775 7448 904BX Mon F. Teyssier 21/01/2017 4207 7162 11000BX Mon P. Somogyi 21/01/2017 4231 7194 709CH Cyg F. Teyssier 21/01/2017 4207 7162 11000EG And F. Teyssier 02/01/2017 4207 7162 11000EG And J. Guarro 12/01/2017 3775 7448 1056EG And F. Teyssier 17/01/2017 4207 7162 11000EG And F. Teyssier 26/01/2017 4250 7150 11000EG And J. Guarro 28/01/2017 3736 7448 1109GH Gem F. Boubault 07/01/2017 4003 7502 2200NQ Gem F. Teyssier 21/01/2017 4207 7162 11000NQ Gem V. Lecocq 21/01/2017 4201 7300 532NQ Gem D. Boyd 24/01/2017 3901 7380 718NQ Gem P. Berardi 25/01/2017 6326 6796 5507omi Cet J. Guarro 14/01/2017 3832 7435 972R Aqr J. Guarro 12/01/2017 3802 7448 1021SU lyn D. Boyd 09/01/2017 3901 7380 709SU lyn F. Teyssier 21/01/2017 4300 7150 11000T CrB F. Teyssier 21/01/2017 4207 7162 11000T CrB P. Somogyi 21/01/2017 4234 7197 730TX CVn P. Somogyi 21/01/2017 4234 7196 727UV Aur J. Guarro 12/01/2017 3815 7448 1090UV Aur D. Boyd 13/01/2017 3900 7380 740UV Aur J. Guarro 28/01/2017 3758 7448 903V627 Cas J. Guarro 13/01/2017 4114 7432 1006V627 Cas D. Boyd 20/01/2017 3901 7380 732V694 Mon P. Somogyi 08/01/2017 4189 7145 553V694 Mon P. Somogyi 20/01/2017 4233 7192 721V694 Mon P. Somogyi 21/01/2017 4267 7225 755V694 Mon P. Somogyi 22/01/2017 4250 7212 751Z And F. Teyssier 02/01/2017 4300 7150 11000Z And J. Guarro 12/01/2017 3785 7448 1060Z And D. Boyd 13/01/2017 3900 7380 725Z And F. Teyssier 19/01/2017 4300 7150 11000Z And F. Teyssier 26/01/2017 4300 7150 11000ZZ Cmi J. Guarro 28/01/2017 3758 7448 1039
Range (A)
ARAS Eruptive Stars Information Letter 2017-01 - p. 4
AG Dra
Coordinates (2000.0)R.A. 16 01 41.0Dec +66 48 10.1Mag V 9.8
SYMBIOTICS
9
9.5
102457390 2457480 2457570 2457660 2457750 2457840
AG Dra (V)
4000 4500 5000 5500 6000 6500 7000
Wavelength (A)
0
1
2
3
4
5
6
7
Flu
x [e
rg.c
m-2
.s-1
.Å-1
]
10-12 AGDra 2017-01-13 18:02:45 R = 1000 D. Boyd
4000 4500 5000 5500 6000 6500 7000
Wavelength (A)
0
5
10
15
rela
tive
in
ten
sity
AG Dra 2017-01-21 02:28:32 R = 730 P. Somogyi
The yellow symbiotic star AG Dra in quiescenceSpectra obtained by David Boyd (LISA R = 1000, flux calibrated) and Peter Somogyi (Lhires III 150 l/mm R = 700) give EW(Raman OVI) at 6.7 and 7.1 respectively
ARAS Eruptive Stars Information Letter 2017-01 - p. 5
AG Peg
Coordinates (2000.0)R.A. 21 51 02.0Dec +12 37 32.1Mag V 8.9 (dec. 2016)
SYMBIOTICS
ARAS Eruptive Stars Information Letter 2017-01 - p. 6
8
8.5
92457560 2457620 2457680 2457740 2457800
AG Peg (V)
Quiescent state after its historical double outburst in 2015-2016. Small increase of luminosity in Juanuary
4000 4500 5000 5500 6000 6500 7000
Wavelength (A)
0
10
20
30
40
50
rela
tive
in
ten
sity
AG Peg 2017-01-25 18:10:40 R = 1000 F Boubault
4000 4500 5000 5500 6000 6500 7000
Wavelength (A)
0
1
2
3
4
5
6
Flu
x [e
rg.c
m-2
.s-1
.Å-1
]
10-11 AG Peg 2017-01-19 17:36:42 R = 1000 D. Boyd
AG Peg at R = 11000SYMBIOTICS
ARAS Eruptive Stars Information Letter 2017-01 - p. 7
8
8.5
9
9.52457560 2457620 2457680 2457740 2457800
AG Peg (V)
-500 -250 0 250 500
velocity (km/s)
0
20
40
60
80
100
120
arb
itra
ry u
nit
AGPeg | Ha 6563
2016-07-090.279
2016-08-060.313
2016-08-160.325
2016-08-230.334
2016-09-090.354
2016-10-010.381
2016-10-290.415
2016-11-150.436
2016-11-290.453
2016-12-160.474
2017-01-020.495
phase
-500 -250 0 250 500
velocity (km/s)
0
20
40
60
80
100
120
140
arb
itra
ry u
nit
AGPeg | Hb 4861
2016-07-090.279
2016-08-060.313
2016-08-160.325
2016-08-230.334
2016-09-090.354
2016-10-010.381
2016-10-290.415
2016-11-150.436
2016-11-290.453
2016-12-160.474
2017-01-020.495
phase
-500 -250 0 250 500
velocity (km/s)
0
5
10
15
20
25
30
arb
itra
ry u
nit
AGPeg | He I 5876
2016-07-090.279
2016-08-060.313
2016-08-160.325
2016-08-230.334
2016-09-090.354
2016-10-010.381
2016-10-290.415
2016-11-150.436
2016-11-290.453
2016-12-160.474
2017-01-020.495
phase
-500 -250 0 250 500
velocity (km/s)
0
50
100
150
arb
itra
ry u
nit
AGPeg | He II 4686
2016-07-090.279
2016-08-060.313
2016-08-160.325
2016-08-230.334
2016-09-090.354
2016-10-010.381
2016-10-290.415
2016-11-150.436
2016-11-290.453
2016-12-160.474
2017-01-020.495
phase
-500 -250 0 250 500
velocity (km/s)
0
5
10
15
arb
itra
ry u
nit
AGPeg | [Fe VII] 6087
2016-07-090.279
2016-08-060.313
2016-08-160.325
2016-08-230.334
2016-09-090.354
2016-10-010.381
2016-10-290.415
2016-11-150.436
2016-11-290.453
2016-12-160.474
2017-01-020.495
phase
AX PerSYMBIOTICS
ARAS Eruptive Stars Information Letter 2017-01 - p. 8
Coordinates (2000.0)R.A. 01 36 22.7Dec +54 15 02.4
Top: AAVSO Blue and Green LightcurveARAS Spectra duing the current eclipse: blue dots
The classical symbiotic AX Per is re-brightening during its current eclipse.
Observations of AX Per until the end of the eclipse is strongly recom-manded
10.5
11
11.5
12
12.52457600 2457650 2457700 2457750 2457800
AX Per (V)
11
11.5
12
12.5
13
13.5
10.5
11
11.5
12
12.52457300 2457400 2457500 2457600 2457700 2457800 2457900
AX Per (V)
0.5
1
1.5
0.5
1
1.52457300 2457400 2457500 2457600 2457700 2457800 2457900
AX Per (B-V)
The current eclipse from AAVSO databaseTop : V and B band (resp. left and right scale)Bottom : B-V reaching a maximum value of 1.24 *after* the minimum
10
10.5
11
11.5
12
12.5
130 0.25 0.5 0.75 1
Comparison of V magnitude during the current eclipse (blue dots) and the former one (green dots)Strong difference of the shape and deepest eclipse for the former eclipseNote also the minimum at phase ~0.47 for the current eclipse but maximum B-V value is measured at phase 0.5
AX PerSYMBIOTICS
ARAS Eruptive Stars Information Letter 2017-01 - p. 9
4000 4500 5000 5500 6000 6500 7000
Wavelength (A)
0
10
20
30
40
rela
tive
in
ten
sity
AX Per 2017-01-21 20:35:56 R = 1000 F Boubault
4000 4500 5000 5500 6000 6500 7000
Wavelength (A)
0
5
10
15
20
25
rela
tive
in
ten
sity
AX Per 2017-01-06 20:15:39 R = 700 J. Guarro
4000 4500 5000 5500 6000 6500 7000
Wavelength (A)
0
10
20
30
40
50
rela
tive
in
ten
sity
AX Per 2017-01-20 20:43:30 R = 709 P. Somogyi
AX Per in January at R ~ 1000Joan Guarro : home made spectrographPeter Somogyi : Lhires III 150 l/mmFranck Boubault : Lisa
AX PerSYMBIOTICS
David Boyd’s monitoringLISA R = 1000Flux calibrated spectra
ARAS Eruptive Stars Information Letter 2017-01 - p. 10
4000 4500 5000 5500 6000 6500 7000
Wavelength (A)
0
0.5
1
1.5
2
2.5
3
Flu
x [e
rg.c
m-2
.s-1
.Å-1
]
10-12 AX Per 2017-01-05 18:28:05 R = 721 D. Boyd
4000 4500 5000 5500 6000 6500 7000
Wavelength (A)
0
0.5
1
1.5
2
2.5
3
flu
x (
erg
cm
- 2 s
- 1 A
- 1)
10-12 AX Per 2017-01-20 19:58:07 R = 719 D. Boyd
4000 4500 5000 5500 6000 6500 7000
Wavelength (A)
0
0.5
1
1.5
2
2.5
3
flu
x (
erg
cm
- 2 s
- 1 A
- 1)
10-12 AX Per 2017-01-28 19:55:50 R = 736 D. Boyd
AX PerSYMBIOTICS
-1000 -500 0 500 1000
velocity (km/s)
0
20
40
60
rela
tive
in
ten
sity
Halpha 2017-01-18
-1000 -500 0 500 1000
velocity (km/s)
0
10
20
30
40
50
rela
tive
in
ten
sity
Hbeta 2017-01-18
-1000 -500 0 500 1000
velocity (km/s)
0
5
10
15
rela
tive
in
ten
sity
HeI5876 2017-01-18
-1000 -500 0 500 1000
velocity (km/s)
0
10
20
30
40
rela
tive
in
ten
sity
HeII4686 2017-01-18
-1000 -500 0 500 1000
velocity (km/s)
0
2
4
6
rela
tive
in
ten
sity
[FeVII]6087 2017-01-18
-1000 -500 0 500 1000
velocity (km/s)
0
1
2
3
4
rela
tive
in
ten
sity
[OIII]5007 2017-01-18
6350 6450 6550 6650 6750
Wavelength (A)
0
10
20
30
40
rela
tive
in
ten
sity
AX Per 2017-01-26 17:28:50 R = 5547 Paolo Berardi
-1000 -500 0 500 1000
velocity (km/s)
0
10
20
30
40
rela
tive
in
ten
sity
Halpha 2017-01-26
H alpha range obtained by Paolo Berardi with a Lhires III 1200 l/mmand crop on H alpha line
Bottom : main lines from eshel spectrum (F. Teyssier )
ARAS Eruptive Stars Information Letter 2017-01 - p. 11
BF Cyg
Coordinates (2000.0)R.A. 3 42 9.3 Dec 63 13 0.5 Mag
SYMBIOTICS
ARAS Eruptive Stars Information Letter 2017-01 - p. 12
BD CamSYMBIOTICS
4000 4500 5000 5500 6000 6500 7000
Wavelength (A)
0
0.5
1
1.5
2
2.5
rela
tive
in
ten
sity
BD Cam 2017-01-25 19:18:42 R = 1000 F Boubault
4000 4500 5000 5500 6000 6500 7000
Wavelength (A)
0
0.5
1
1.5
2
rela
tive
in
ten
sity
BD Cam 2017-01-12 22:26:03 R = 1082 J. Guarro
BF CygSYMBIOTICS
BD CamSYMBIOTICS
4500 5000 5500 6000 6500 7000
Wavelength (A)
0
0.5
1
1.5
2
2.5
rela
tive
in
ten
sity
BD Cam 2017-01-20 23:28:38 R = 11000 Olivier Garde
-500 0 500
velocity (km/s)
0
0.5
1
1.5
2
rela
tive
in
ten
sity
Halpha 2017-01-20
-500 0 500
velocity (km/s)
0
0.5
1
1.5
Flu
x
Hbeta 2017-01-20
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
Rel
ativ
e in
tens
ity
5850 5860 5870 5880 5890 5900 5910 5920Wavelength (Angstrom)
Na I - BD Cam 2017-01-20.978 6647 s (11 x 600 s) Olivier Garde
Balmer lines in absorption
Na I D range
ARAS Eruptive Stars Information Letter 2017-01 - p. 13
BX Mon
Coordinates (2000.0)R.A. 7 25 24Dec -3 36 0Mag 9.8 (2016-12)
SYMBIOTICS
An interesting target for winter nights
ARAS Eruptive Stars Information Letter 2017-01 - p. 14
99.510
10.511
11.512
12.5132451000 2454650 2458300
BX Mon (V)
4500 5000 5500 6000 6500 7000
Wavelength (A)
0
1
2
3
4
5
6
rela
tive
in
ten
sity
BX Mon 2017-01-21 00:33:16 R = 709 P. Somogyi
-1000 -500 0 500 1000
velocity (km/s)
0
2
4
6
8
rela
tive
in
ten
sity
Halpha 2017-01-21
-500 0 500
velocity (km/s)
0.4
0.6
0.8
1
1.2
rela
tive
in
ten
sity
HeI5876 2017-01-21
-500 0 500
velocity (km/s)
1
1.2
1.4
1.6
1.8
2
rela
tive
in
ten
sity
[OI]6300 2017-01-21
4500 5000 5500 6000 6500 7000
Wavelength (A)
0
2
4
6
8
rela
tive
in
ten
sity
BX Mon 2017-01-21 21:12: R = 11000 F Teyssier
CH Cyg
Coordinates (2000.0)R.A. 19 24 33.1Dec +50 14 29.1Mag
SYMBIOTICS
Ongoing campaign upon the request of Augustin SkopalAt least one spectrum a month (high resolution and low resolution, with a cor-rect atmospheric response)
ARAS Eruptive Stars Information Letter 2017-01 - p. 15
AAVSO V lightcurve (2015-2016) and ARAS spectra (blue dots) in Juanuary
4500 5000 5500 6000 6500 7000
Wavelength (A)
0
5
10
15
rela
tive
in
ten
sity
CH Cyg 2017-01-21 05:41:26 R = 11000 F Teyssier
6
6.5
7
7.5
8
8.5
92457000 2457180 2457360 2457540 2457720 2457900
CH Cygni (V)
SYMBIOTICS
CH Cyg Evolution since October2016
ARAS Eruptive Stars Information Letter 2017-01 - p. 16
Echelle spectraR = 11000F. TeyssierJ. Guarro
See Steve’s comments about Na I D
7
7.5
8
8.5
92457600 2457690 2457780
CH Cygni (V)
-500 -250 0 250 500
velocity (km/s)
0
20
40
60
80
100
120
arb
itra
ry u
nit
CHCyg | Ha 6563
2016-10-01
2016-10-05
2016-10-09
2016-10-18
2016-10-26
2016-11-14
2016-11-25
2016-11-29
2016-12-04
2016-12-12
2016-12-27
2017-01-21
-500 -250 0 250 500
velocity (km/s)
0
10
20
30
40
50
60
70
80
arb
itra
ry u
nit
CHCyg | Hb 4861
2016-10-01
2016-10-05
2016-10-09
2016-10-18
2016-10-26
2016-11-14
2016-11-25
2016-11-29
2016-12-04
2016-12-12
2016-12-27
2017-01-21
-500 -250 0 250 500
velocity (km/s)
0
5
10
15
20
25
arb
itra
ry u
nit
CHCyg | He I 5876
2016-10-01
2016-10-05
2016-10-09
2016-10-18
2016-10-26
2016-11-14
2016-11-25
2016-11-29
2016-12-04
2016-12-12
2016-12-27
2017-01-21
-500 -250 0 250 500
velocity (km/s)
0
2
4
6
8
10
12
14
arb
itra
ry u
nit
CHCyg | Na ID 5890
2016-10-01
2016-10-05
2016-10-09
2016-10-18
2016-10-26
2016-11-14
2016-11-25
2016-11-29
2016-12-04
2016-12-12
2016-12-27
2017-01-21
-500 -250 0 250 500
velocity (km/s)
0
5
10
15
20
25
30
35
40
45
50
arb
itra
ry u
nit
CHCyg | [O III] 5007
2016-10-01
2016-10-05
2016-10-09
2016-10-18
2016-10-26
2016-11-14
2016-11-25
2016-11-29
2016-12-04
2016-12-12
2016-12-27
2017-01-21
-500 -250 0 250 500
velocity (km/s)
0
5
10
15
20
25
30
arb
itra
ry u
nit
CHCyg | [OI] 6300
2016-10-01
2016-10-05
2016-10-09
2016-10-18
2016-10-26
2016-11-14
2016-11-25
2016-11-29
2016-12-04
2016-12-12
2016-12-27
2017-01-21
GH GemSYMBIOTICS
Coordinates (2000.0)R.A. 07 04 12.78Dec +12 03 34.3Mag 12.5 (02-2017)
4500 5000 5500 6000 6500 7000
Wavelength (A)
0
0.5
1
1.5
rela
tive
in
ten
sity
GH Gem 2017-01-07 21:25: R = 1000 F Boubault
ARAS Eruptive Stars Information Letter 2017-01 - p. 17
NQ GemSYMBIOTICS
Coordinates (2000.0)R.A. 07 31 54.5Dec +24 30 12.5Mag 8.0 (01-2017)
4000 4500 5000 5500 6000 6500 7000
Wavelength (A)
0
0.5
1
1.5
rela
tive
in
ten
sity
NQ Gem 2017-01-21 21:08:45 R = 532 V. Lecocq
4000 4500 5000 5500 6000 6500 7000
Wavelength (A)
0
1
2
3
4
5
6
Flu
x [e
rg.c
m-2
.s-1
.Å-1
]
10-12 NQ Gem 2017-01-24 20:50:46 R = 718 D. Boyd
Carbon symbiotic NQ Gem obtained by Vincent Lecoq with an Alpy and David Boyd with LISA (flux calibrated) . A good test of the resolution between the two spectroscopes (resp. R = 600 and 1000)
ARAS Eruptive Stars Information Letter 2017-01 - p. 18
NQ GemSYMBIOTICS
6400 6500 6600 6700 6800
Wavelength (A)
0
0.5
1
1.5
2
rela
tive
in
ten
sity
NQ Gem 2017-01-25 18:48:57 R = 5507 Paolo Berardi
H alpha range by Paolo Berardi with Lhires III 1200 l/mm
4000 4500 5000 5500 6000 6500 7000
Wavelength (A)
0
0.5
1
1.5
2
2.5
rela
tive
in
ten
sity
NQ Gem 2017-01-21 19:36:35 R = 11000 F Teyssier
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
Rel
ativ
e in
tens
ity
5850 5860 5870 5880 5890 5900 5910 5920Wavelength (Angstrom)
Na I - NQ Gem 2017-01-21.817 4826 s (8 x 600 s) fteyssier
ARAS Eruptive Stars Information Letter 2017-01 - p. 19
omi CetSYMBIOTICS
Coordinates (2000.0)R.A. 02 19 20.79Dec -02 58 39.5Mag (01-2017)
23456789
10112456815 2457180 2457545 2457910
o Cet (Vis )
4000 4500 5000 5500 6000 6500 7000
Wavelength (A)
0
1
2
3
4
5
rela
tive
in
ten
sity
Omi Cet 2017-01-14 18:14:25 R = 972 J. Guarro
The symbiotic mira near its maximumFaint Hd emission in Joan Guaro’s spectrum
ARAS Eruptive Stars Information Letter 2017-01 - p. 20
R AqrSYMBIOTICS
Coordinates (2000.0)R.A. 23 43 49.4Dec -15 17 4.2Mag 11.0 (12-2016)
ARAS Eruptive Stars Information Letter 2017-01 - p. 21
The symbiotic Mira R Aqr near its minimum with strong [O III] emissions, rising
Project : evolution along several pulsations
AAVSO Visual (10 days mean)
4000 4500 5000 5500 6000 6500 7000
Wavelength (A)
0
5
10
15
rela
tive
in
ten
sity
R Aqr 2017-01-12 18:02:21 R = 1021 J. Guarro
6
7
8
9
10
11
12
132457000 2457365 2457730 2458095
R Aqr
SU LynSYMBIOTICS
ARAS Eruptive Stars Information Letter 2017-01 - p. 22
Coordinates (2000.0)R.A. 06 42 55.1Dec +55 28 27.2Mag 8.50 (2017-01)
4000 4500 5000 5500 6000 6500 7000
Wavelength (A)
0
0.2
0.4
0.6
0.8
1
Flu
x [e
rg.c
m-2
.s-1
.Å-1
]
10-11 SU Lyn 2017-01-09 20:52:30 R = 709 D. Boyd
ARAS Eruptive Stars Information Letter 2017-01 - p. 22
SU Lyn is newly discovered bright symbiotic (K. Mukai, 2016)
It shows strong orbital variation of H alpha line. Further observations are strongly encouraged
6500 6550 6600 6650
Wavelength (A)
0.5
1
1.5
2
rela
tive
in
ten
sity
SU Lyn 2017-01-21 18:05:23 R = 11000 F Teyssier
H alpha range
SU LynSYMBIOTICS
0.5
1
1.5
2
2.5
3
Rel
ativ
e in
tens
ity
-1000 -500 500 1000Velocity (Km/sec)
2016-05-04.8682017-01-21.754
Halpha - SU Lyn fteyssier
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
Rel
ativ
e in
tens
ity
-500 -250 250 500Velocity (Km/sec)
2016-05-04.8682017-01-21.754
[O III] - SU Lyn fteyssier
0.1
0.2
0.3
0.4
0.5
0.6
0.7R
elat
ive
inte
nsity
-500 -250 250 500Velocity (Km/sec)
2016-05-04.8682017-01-21.754
Hbeta - SU Lyn fteyssier
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
Rel
ativ
e in
tens
ity
-500 -250 250 500Velocity (Km/sec)
[O III] 4958.91[O III] 5006.84
SU Lyn 2016-05-04.868 3114 s (9 x 300 s) fteyssier
0.050.1
0.150.2
0.250.3
0.350.4
0.450.5
Rel
ativ
e in
tens
ity
5850 5860 5870 5880 5890 5900 5910 5920Wavelength (Angstrom)
2016-05-04.8682017-01-21.754
Na I - SU Lyn fteyssier
ARAS Eruptive Stars Information Letter 2017-01 - p. 23
Comparison of [OIII] 5007 and 4959 lines,as a confirmation of [OIII] 5007
Variation of stellar Na I D lines
4300 4800 5300 5800 6300
Wavelength (A)
0
0.5
1
1.5
2
2.5
3
3.5re
lative
in
ten
sity
SU Lyn 2017-01-21 18:05:23 R = 11000 F Teyssier
T CrBSYMBIOTICS
Coordinates (2000.0)R.A. 15 59 30.1Dec 25 55 12.6Mag 9.8 (2017-01)
ARAS Eruptive Stars Information Letter 2017-01 - p. 24
JD +
1000 2000 3000 4000 5000 6000 7000 8000
9
9.5
10
10.5
11
Ma
gn
itu
de
V
2000 2002 2004 2006 2008 2010 2012 2014 20169
9.5
10
10.5
11
9
9.5
10
10.52457300 2457400 2457500 2457600 2457700 2457800
T CrB
AAVSO V light curve 2016-2017
The 2015 visual outburst of 2016. T CrB is a main target in our observing program for the next years until the next nova event.
T CRB in the morning sky
4500 5000 5500 6000 6500 7000
Wavelength (A)
0
5
10
15
20
rela
tive
in
ten
sity
T CrB 2017-01-21 04:09:45 R = 11000 F Teyssier
T CrB 2016-2017SYMBIOTICS
-1000 -500 0 500 1000
velocity (km/s)
0
10
20
30
40
50
60
70
80
90
100
arb
itra
ry u
nit
TCrB | Hb 4861
2016-02-170.711
2016-02-290.736
2016-04-010.802
2016-04-140.829
2016-04-160.833
2016-04-230.847
2016-04-280.858
2016-04-300.862
2016-05-140.891
2016-06-080.942
2016-06-250.977
2016-07-060.000
2016-07-160.021
2016-08-050.062
2016-08-220.097
2017-01-210.412
phase
-1000 -500 0 500 1000
velocity (km/s)
0
5
10
15
20
25
30
35
arb
itra
ry u
nit
TCrB | He I 5876
2016-02-170.711
2016-02-290.736
2016-04-010.802
2016-04-140.829
2016-04-160.833
2016-04-230.847
2016-04-280.858
2016-04-300.862
2016-05-140.891
2016-06-080.942
2016-06-250.977
2016-07-060.000
2016-07-160.021
2016-08-050.062
2016-08-220.097
2017-01-210.412
phase
-500 -250 0 250 500
velocity (km/s)
0
2
4
6
8
10
12
14
16
18
20
arb
itra
ry u
nit
TCrB | [O III] 5007
2016-02-170.711
2016-02-290.736
2016-04-010.802
2016-04-140.829
2016-04-160.833
2016-04-230.847
2016-04-280.858
2016-04-300.862
2016-05-140.891
2016-06-080.942
2016-06-250.977
2016-07-060.000
2016-07-160.021
2016-08-050.062
2016-08-220.097
2017-01-210.412
phase
-500 -250 0 250 500
velocity (km/s)
0
10
20
30
40
50
60
70
80
90
100
arb
itra
ry u
nit
TCrB | Ha 6563
2016-02-170.711
2016-02-290.736
2016-04-010.802
2016-04-140.829
2016-04-160.833
2016-04-230.847
2016-04-280.858
2016-04-300.862
2016-05-140.891
2016-06-080.942
2016-06-250.977
2016-07-060.000
2016-07-160.021
2016-08-050.062
2016-08-220.097
2017-01-210.412
phase
F. TeyssierEshel R = 11000
Note the significant change be-tween August,2016 and Janu-
9
9.5
10
10.52457400 2457500 2457600 2457700 2457800
T CrB
ARAS Eruptive Stars Information Letter 2017-01 - p. 25
T CrBSYMBIOTICS
ATEL #10046 Title: Dramatic change in the X-ray spectrum of symbiotic recurrent nova T CrBAuthor: Luna G. J. M. (IAFE/CONICET), Mukai K. (NASA GSFC), Sokoloski J. L., Lucy A. (Columbia), Nelson T. (Pittsburgh), Nunez N. (ICATE/CONICET)Posted: 3 Feb 2017; 17:32 UT
We report the results from two Swift XRT/UVOT observations of the recurrent novae T CrB, performed on 01/18/2017 and 01/29/2017. In April 2016, T CrB reached the peak of an optical brightening event (Delta V~1, Delta B~1.5) that started at the beginning of 2015 (Munari et al. 2016) and is slowly de-clining toward the quiescence level of V~10. A similar brightening event of unknown origin was also observed around 8 years before the nova eruptions of 1866 and 1946, when T CrB brightened up to V~3 (Schaefer 2014). Using the BAT transient monitor, we have made the surprising discovery that T CrB has undergone a shallow decline in its hard X-ray flux starting at roughly the time of the optical peak in April 2016. For the past 200 days, T CrB has been undetected by the Swift BAT Daily Monitor.
The overall decline in high energy flux is confirmed by our Swift XRT observations, with source count rates of 0.009 c/s on 01/18/2017 and 0.014 c/s on 01/29/2017 in the 0.3-10 keV energy range. Comparing an XRT count rate of 0.082 c/s measured in the 0.3-10.0 keV range in 2005 with our two recent Swift XRT ob-servations, the X-ray flux has declined by a factor of ~10 and ~6 in the two observations, respectively. Even more interesting is that the hardness ratio, F(2.0-10.0 keV)/F(0.3-2.0 keV), decreased a factor of ~100.This change is due to the appearance of a new, distinct, soft X-ray component with E <~ 1 keV. While previous X-ray observations (Luna et al. 2008, Ilkiewicz et al. 2016) suggested that T CrB had a delta-type X-ray spectrum as described by Luna et al. (2013), the detection of the soft compo-nent indicates that it now has a mixed beta/delta-type spectrum. The hard component of the XRT spectra can be described by a highly absorbed (nh > 10^23 cm^-2), optically thin thermal plasma (kT > 5 keV) while the new soft component can be described by either an optically thin thermal plasma with a temperature of kT = 0.07+-0.02 keV or a blackbody with about the same tempera-ture. The blackbody normalization implies an unabsorbed luminosity of a 6e31 ergs/s (d/1 kpc)^2.
The Swift/UVOT UVM2 observations saturated, with magnitudes < 10. Previous ob-servations (between 2005 and 2015) showed a UVM2 magnitude of about 14.90.
In Kennea et al. (2009) and Luna et al. (2008) we reported Swift BAT and Suzaku observations and proposed that the high-energy X-rays originate From_a highly absorbed, optically thin ther-mal plasma in the most internal part of the accretion disk, i.e. the boundary layer. The current de-cline in BAT flux could thus be due to a change in the optical depth of this region, likely after an in-crease in the accretion rate through the disk (as in dwarf novae outbursts). Such a change could also explain the optical brightening. The drop in X-ray hardness ratio as well as the increase in UV flux would also be expected in this picture. Swift detected both effects in our recent observations.
We will continue monitoring this unique event with Swift, and we encourage fur-ther observations at other wavelengths. We thank the Swift team, in particular Neil Geh-rels, for the fast response time in executing this target-of-opportunity observation.
ARAS Eruptive Stars Information Letter 2017-01 - p. 26
TX CVnSYMBIOTICS
Coordinates (2000.0)R.A. 12 44 42.06Dec +36 45 50.7Mag 10.3 (01-2017)
4500 5000 5500 6000 6500 7000
Wavelength (A)
0.5
1
1.5
rela
tive
in
ten
sity
TX CVn 2017-01-21 01:34:46 R = 727 P. Somogyi
ARAS Eruptive Stars Information Letter 2017-01 - p. 27
UV AurSYMBIOTICS
ARAS Eruptive Stars Information Letter 2017-01 - p. 28
Coordinates (2000.0)R.A. 5 21 48.8Dec 32 30 43.1Mag 9.2 (2016-12)
Near the minimum of the pulsation cycle
8
8.5
9
9.5
10
10.5
112456900 2457265 2457630 2457995
UV Aur (V)
4000 4500 5000 5500 6000 6500 7000
Wavelength (A)
0
0.5
1
1.5
flu
x (
erg
cm
- 2 s
- 1 A
- 1)
10-12 UV Aur 2017-01-13 21:57:54 R = 740 D. Boyd
4000 4500 5000 5500 6000 6500 7000
Wavelength (A)
0
0.5
1
1.5
rela
tive
in
ten
sity
UV Aur 2017-01-28 21:29:02 R = 903 J. Guarro
V627 CasSYMBIOTICS
Coordinates (2000.0)R.A. 22 57 41.2 Dec 58 49 14.9Mag 12.2 (2017-01)
ARAS Eruptive Stars Information Letter 2017-01 - p. 29
4000 4500 5000 5500 6000 6500 7000
Wavelength (A)
0
1
2
3
4
5
6
Flu
x [e
rg.c
m-2
.s-1
.Å-1
]
10-13 V627 Cas 2017-01-20 18:18:02 R = 732 D. Boyd
4000 4500 5000 5500 6000 6500 7000
Wavelength (A)
0
0.5
1
1.5
2
2.5
rela
tive
in
ten
sity
V627 Cas 2017-01-13 17:45:02 R = 1006 J. Guarro
12
12.2
12.4
12.6
12.8
132457180 2457545 2457910
V627 Cas (V)
V627 Cas is a poorly observed symbiotic star (suspected)
Description of the star by M. Gromadzki et al. (2006)V627 Cas was initially classified as T Tau variable (Paupers et al. 1989), whereas Kolotilov (1998) pro-posed its symbiotic nature. It was included on the Belczynski et al. (2000) list of stars suspected to be symbiotic. The spectral type of the cool compo-nent is M2-4II (Kolotilov et al. 1991). Pulsations with a period of ≈ 466 days and brightness changes from night to night, indicating possible presence of flicker-ing, were reported by Kolotilov et al. (1991, 1996). It has been suggested that the V627 Cas hot com-panion activity is of similar nature as that of CH Cyg.Kolotilov et al. (1991) also observed short-lived flares with amplitude of about 0.5 mag in B.
The AAVSO lightcurve (David Boyd’s obser-vations) showing the pulsation of the giant.
From these data, the period estimated with Period04 is 337 (+/- 3) days much short-er than that reported by Kolotilov et al.
ARAS Eruptive Stars Information Letter 2017-01 - p. 29
V694 MonSYMBIOTICS
Coordinates (2000.0)R.A. 7 25 51.2Dec -7 44 8Mag
V694 Mon remains at high luminosity (Mean mag ~9.5)
Observations during all the season are strongly encouraged.
ARAS Eruptive Stars Information Letter 2017-01 - p. 30
4500 5000 5500 6000 6500 7000
Wavelength (A)
0
2
4
6
8
10
rela
tive
in
ten
sity
V694 Mon 2017-01-08 20:43:27 R = 553 P. Somogyi
4500 5000 5500 6000 6500 7000
Wavelength (A)
0
2
4
6
8
10
12
rela
tive
in
ten
sity
V694 Mon 2017-01-22 20:04:23 R = 751 P. Somogyi
8.5
9
9.5
10
10.5
112457000 2457365 2457730 2458095
V694 Mon
Z And
Coordinates (2000.0)R.A. 23 33 39.9Dec +48 49 06.0Mag 10.3 (2017-01)
SYMBIOTICS
ARAS Eruptive Stars Information Letter 2017-01 - p. 31 ARAS Eruptive Stars Information Letter 2017-01 - p. 31
velocity (km/s)
-500 0 500
relat
ive in
tens
ity
0
2
4
6
8HeI5876 2016-07-14
velocity (km/s)
-500 0 500
relat
ive in
tens
ity
0.5
1
1.5
2
2.5[FeVII]6087 2016-07-14
velocity (km/s)
-500 0 500
relat
ive in
tens
ity
0
2
4
6[OIII]5007 2016-07-14
4000 4500 5000 5500 6000 6500 7000
Wavelength (A)
0
5
10
15
20
rela
tive
in
ten
sity
Z And 2017-01-12 18:48:29 R = 1060 J. Guarro
4000 4500 5000 5500 6000 6500 7000
Wavelength (A)
0
2
4
6
8
Flu
x [e
rg.c
m-2
.s-1
.Å-1
]
10-12 Z And 2017-01-13 20:13:47 R = 1000 D. Boyd
9.5
10
10.52457400 2457500 2457600 2457700 2457800
Z And (V)
-500 -250 0 250 500
velocity (km/s)
0
10
20
30
40
50
60
70
80
90
100
arb
itra
ry u
nit
ZAnd | Ha 6563
2016-07-140.647
2016-08-260.704
2016-09-230.741
2016-11-300.830
2017-01-020.874
2017-01-190.896
2017-01-260.906
phase
-500 -250 0 250 500
velocity (km/s)
0
2
4
6
8
10
12
14
16
18
20
arb
itra
ry u
nit
ZAnd | He I 5876
2016-07-140.647
2016-08-260.704
2016-09-230.741
2016-11-300.830
2017-01-020.874
2017-01-190.896
2017-01-260.906
phase
-500 -250 0 250 500
velocity (km/s)
0
10
20
30
40
50
60
70
80
arb
itra
ry u
nit
ZAnd | He II 4686
2016-07-140.647
2016-08-260.704
2016-09-230.741
2016-11-300.830
2017-01-020.874
2017-01-190.896
2017-01-260.906
phase
-250 -125 0 125 250
velocity (km/s)
0
2
4
6
8
10
12
14
16
arb
itra
ry u
nit
ZAnd | [Fe VII] 6087
2016-07-140.647
2016-08-260.704
2016-09-230.741
2016-11-300.830
2017-01-020.874
2017-01-190.896
2017-01-260.906
phase
-250 -125 0 125 250
velocity (km/s)
0
2
4
6
8
10
12
14
16
18
20
22
arb
itra
ry u
nit
ZAnd | [O III] 5007
2016-07-140.647
2016-08-260.704
2016-09-230.741
2016-11-300.830
2017-01-020.874
2017-01-190.896
2017-01-260.906
phase
-250 -125 0 125 250
velocity (km/s)
0
10
20
30
40
50
60
70
80
arb
itra
ry u
nit
ZAnd | Hb 4861
2016-07-140.647
2016-08-260.704
2016-09-230.741
2016-11-300.830
2017-01-020.874
2017-01-190.896
2017-01-260.906
phase
Z And 2016-2017SYMBIOTICS
9.5
10
10.52457400 2457500 2457600 2457700 2457800
Z And (V)
F. TeyssierEshel R = 11000
ARAS Eruptive Stars Information Letter 2017-01 - p. 32
ZZ CMi
Coordinates (2000.0)R.A. 07 24 14.0Dec +08 53 51.8Mag 10.1 (2017-01)
SYMBIOTICS
4000 4500 5000 5500 6000 6500 7000
Wavelength (A)
0
1
2
3
4
rela
tive
in
ten
sity
ZZ CMi 2017-01-28 22:58:57 R = 1039 J. Guarro
ARAS Eruptive Stars Information Letter 2017-01 - p. 33
V SgeNOVA
LIKE
Coordinates (2000.0)R.A. 20 20 14.69Dec +21 06 10.4Mag
4500 4600 4700 4800 4900 5000 5100 5200 5300
Wavelength (A)
0
1
2
3
4
5
6
rela
tive
in
ten
sity
V Sge 2016-07-24 20:29:03 R = 1876 P. Somogyi
He II 4686 and H beta by P. Somogyi (Lhires III - 600 l/mm)
ARAS Eruptive Stars Information Letter 2017-01 - p. 34
CI CamHMXB
Coordinates (2000.0)R.A. 04 19 42.1Dec +55 59 57.7Mag 11.3-11.6 (V)
ARAS Eruptive Stars Information Letter 2017-01 - p. 35
Spectra in ARAS data base:http://www.astrosurf.com/aras/Aras_DataBase/XB/CICam.htm
Ongoing observation of CI Cam by P. Somogyi with a Lhires III - 2400 l/mm
6520 6540 6560 6580 6600
Wavelength (A)
0
20
40
60
80
rela
tive
in
ten
sity
CI Cam 2017-01-07 22:31:25 R = 9241 P. Somogyi
-500 0 500
velocity (km/s)
0
20
40
60
80
100
120
rela
tive
in
ten
sity
Halpha 2017-01-07
CTA 102 = 4C 11.69QUASARS
Coordinates (2000.0)R.A. 22 32 36.4Dec +11 43 51Mag 11.3-11.6 (V)
4500 5000 5500 6000 6500 7000
Wavelength (A)
0
0.5
1
1.5
2
rela
tive
in
ten
sity
4C1169 2017-01-07 19:08:12 R = 2200 F Boubault
4000 4500 5000 5500 6000 6500 7000
Wavelength (A)
0
0.5
1
1.5
2
rela
tive
in
ten
sity
4C1169 2017-01-06 18:14:54 R = 719 J. Guarro
10
11
12
13
14
15
16
17
182457600 2457700
CTA 102 (V)
ARAS Eruptive Stars Information Letter 2017-01 - p. 36
1.1 The gas laws and kinetics
In a normal gas, pressure is a kinetic effect. That is, the collisions (not quite like those on the autoroute but almost) in a normal gas are sufficient to transfer momentum between particles and subject to exter-nal forces there’s a mean velocity and the collective random motion that results from the temperature. This implies that the mean free path, the distance a particle travels before hitting something, is very small compared with the length scales of the medium. In a room, the mean free path is microns or much less, the interaction time scales are nanoseconds, and the gas can be treated as a collective. It’s not quite the same in the rarefied environments you’ve been ob-serving. When you see the [O III] lines, for instance, the implied electron density is less than 107 cm-3, or about 10-13 the density in the air surrounding you as you read this. But consider the scale of the system.In a room the collision length is about 10-9 the size of the room, in the gas of a stellar atmosphere it’s about the same (relatively speaking). So when we speak of a pressure, the random motions of the particles can produce sufficient numbers of close interactions over time scales that scale to the particle crossing time of the system that the medium really seems like a con-tinuous fluid. To be more precise, think of the region in a symbiotic over which a line is formed. This is many times the radius of either of the stellar components.
1.1.1 Temperature?
This brings up two essential, related questions regard-ing the gas laws and their application in astrophysics. One is what temperature means. The other is how can we talk about, for example, shocks or large scale flows without knowing what the speed of sound is. So let’s step back for a moment and examine a detail related to line formation. I’ll try to keep this less technical than sometimes in our discussions but the meaning of thermal processes (i.e. hot and cold) is so deeply rooted in everyday experience that a ri on what hap-pens when the notion doesn’t apply is warranted.
First the microphysical definition (one I remember seeming very weird when I first saw it in school): tem-perature is the parameter that measures the disper-sion in the energy of a gas in kinetic equilibrium. There is a single distribution of the kinetic energies of the in-dividual particles in a volume such that, independent of the number of particles, the chance of randomly drawing one with any particular energy is the same throughout the volume. When we were discussing line formation some time back, you’ll remember that the relative populations of energy levels within an atom when collisions dominate depends only on the temperature. This distribution is why. The collision cross sections depend on energy but the rates are av-erages over all possible collisions (if the gas is in ther-mal equilibrium the microphysical processes all aver-age out) and the temperature of the gas is the same as that obtained from the level populations. This also holds for the emission and absorption of light by the atoms, the radiation is in equilibrium with the mat-ter and the distribution of photon energy is also be labeled with a temperature. In thermal equilibrium, an optically thin gas emits as much energy as a body of the gas temperature would and, if optically thick, that energy is redistributed into the continuum.
1.1.2 Random and ordered motions
To pass out of the technical, you can imagine a gas as consisting of particles whose motion is both or-dered (as I mentioned, by forces acting on all in-dividually an collectively) and a random compo-nent. Remember, whatever its random motion, in a bounding gravitational field (such as a binary star system) every mass, even an atom, feels the cen-tral gravitational attraction of the dominant masses.Were the densities large enough, the atoms would also feel each other, a condition called self- gravita-tion, along with the central body. But this requires that the local mass concentration be greater than the mean density as if the central body were spread out to ll the space surrounding the mass. Even the enormously strong winds of the red supergiants do
A running theme through many of our discussions has been a physical picture of flows and fluids applied to the atmo-spheres, winds, and disks in cosmic sources. François suggested discussing what the speed of sound means for such media, and this also opens the way to spend a few sessions discussing fluids in a general astronomical context. My justification is that you as spectroscopists are able to discern far more than mere fluxes (hence radiative energetics). You see the motions, through comparisons of profiles across species and transitions you have a sort of anemometer.So first, to set the stage, we need to talk about how a gas in the out there can act like a continuum.
Some fluid notions and motionsSteve Shore
ARAS Eruptive Stars Information Letter 2017-01 - p. 37
no have such high spatial densities and, in general, such conditions are only encountered in the extreme environments of protoplanetary or protostellar disks or circumnuclear accretion disks in active galactic nu-clei. So imagine that you have a bunch of atoms falling toward a central mass and you’ll see that if they have random motions each will race out a different orbit, since they won’t either start with the same energy or the same angular momentum, and they’ll form an extended halo whose extent will mimic pressure sup-port even if the matter is collisionless. In this case, the velocity (energy) dispersion of the gas deter-mines the radial distribution and you get something that looks like an isothermal sphere even though temperature really has nothing to do with it. Thermal
1.2 When a gas is a fluid: the sound speed
Now consider that collisions might be possible within the length characteristic of the gas distribution. We imagine a density perturbation, a fluctuation, such that the density is higher in a locale than the sur-rounding gas. This will expand at the rate determined by the dispersion in velocities and if collisions occur, the higher densities will compress the adjacent re-gions that, in turn, will compress their vicinity and so it will go. The disturbance moves outward as a com-pressive, longitudinal wave at the speed depending on the mean thermal energy. This is a sound wave. The compression moves without moving the center of mass only if he amplitude of the disturbance is small. That is, if the density change is only a tiny frac-tion of the surrounding mean density, the compres-sion moves away from the disturbance but there is no net displacement of the gas. Note one thing: of course this is only an approximation, but it may seem confusing. That the disturbance transfers energy without causing a net motion seems counter intuitive but it’s because the wave is weak (and this, actually, defines a simple sound wave). If, however, the ampli-tude is large (the perturbation is of the same order as the mean density, or even greater (if compressed enough), This is, first, a nonlinear wave and when these sorts of waves collide, like the waves approach-ing a beach, other waves emerge at different wave-lengths. This is the basis of turbulence and we’ll cov-er this next month because it’s the basis of much of what you see in stellar photospheres and in the disks.
1.3 Shocks and the damage they do
But there’s another essential result of a large ampli-tude disturbance, one that influences almost all cos-mic sources. If the advancing compression is moving faster than the speed of sound, and this will certain-ly occur if the amplitude of the density perturbation is very large, and if the gas is dense enough to be collisional so we can use the notion of pressure as a mean force due to the velocity dispersion of the particles the medium cannot mechanically adjust rapidly enough to transfer the compression without being physically displaced. This is a shock.The compression raises the temperature because it does work on the impacted upstream gas. And it’s here that we finally get to a special phenomenon that you can observe spectroscopically: the precur-sor. It’s really rather simple. The compressed gas may be so heated, depending on th speed of the front, that it radiates in the ultraviolet. Actually that doesn’t require very high temperatures or compres-sions, a shock of a few hundred km.s-1 suffices. Now that radiation is like a photosphere irradiating the upstream gas. The light passes out of the shock and streams ahead of it. It may travel more slowly than the speed of light if the upstream gas is so opaque that the light passes diffusively, but it will nonethe-less precede the compression and, possibly, pre-ionize the gas. This happens when you have a strong wind emerging from the WD in a symbiotic, or when a symbiotic-like nova erupts and the shock from the explosion passes out of the companion’s wind (as in T CrB, RS Oph, or V407 Cyg). The signature is that narrow lines of highly ionized species appear. But once the shock overtakes that gas, the lines suddenly broaden (as in V407 Cyg during the 2010 outburst). Normal symbiotic outbursts, if they accelerate winds impulsively, are far slower and less effective in ion-izing the gas but the effect may still be present. Only your continuing monitoring can dis-entangle this ef-fect from simple photoionization. The post-shock gas is cooling by this radiation so there is also a change in the ionization and velocity behind the front and this is also visible in spectral changes. We’re really talking here about the same process you see in H II regions except that the velocities here are so large that the gas itself is a radiation source, instead of the central star alone. If the gas is not collisional, howev-er, none of these effects occur so the precursor and
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Some fluid notions and motionsSteve Shore
the dynamical engulfment of the surroundings is an-other demonstration that the gas behaves like a fluid.
1.4 Winds from a kinetic viewpoint
Throughout these newsletters there have been dis-cussions of the lines formed in winds, and even dis-cussion of how they start, but now we can relate them to the gas laws and density-related effects. The outer atmosphere of the Earth, the exosphere, is a region of very low density where ionization produced by impinging solar X-rays and UV produce hot electrons that collisionally couple to the ions and heat the gas. These particles may reach high enough velocities to escape from the atmosphere. Hydrogen is an espe-cially good example, it leaves from the exosphere and forms a sort of planetary evaporative wind. You know this because the scattering of solar Lyman produces a so-called geocorona, an emission line that appears in all satellite UV spectra taken either from low Earth orbit (HST) or toward the Earth’s limb (e.g. IUE). Now if instead we talk about the outer atmosphere of a star, where light from the photosphere is absorbed and re-emitted, the acceleration is produced directly by directional photons. Each of these kicks the atom, only a part of the re-radiation is in the same direc-tion, so the overall effect is that if the medium is op-tically thin in the continuum but thick enough in th absorption lines, there’s a net transfer of momentum outward of the individual species. Then collisions redistribute this kick among all of the surrounding atoms and the gas develops an outward directed pressure gradient, opposite to gravity. If this process suffices to accelerate the atoms of velocities above the sound speed, they continue to flow outwardand produce a density deficit that is relled by a flow from deeper layers. This is a wind, startingfrom the individual kinetic effects. Even if there is no momentum transfer between the atoms, each is given an outward impulse and thus continues to accelerate as each new photon arrives. You could expect to see chemical separation under such cas-es, as indeed happens in th Earth’s exosphere, but in massive stellar winds, and certainly in those we see in symbiotics, the collisions seem sufficient to produce a mean outward flow and chemical strati-fication doesn’t happen. But it’s not impossible.
In fact, there’s an odd property of the solar wind, called the first ionization potential effect (FIP), that the abundance of species in the solar wind depends on their first (from neutral) ionization energy. The solar wind is not radiatively driven, but if this plasma effect can happen in the low density medium of the corona, perhaps it also happens in stellar winds. This would show up in the line profiles as different species having different profiles that don’t merely trace the overall density (there’s something perhaps like this, although merely chemical diffusion, seen in magnetic Ap stars).
Coda
As usual, my thanks. These columns are, I know, be-coming more detailed as we go along but I hope
they remain understandable and interesting. There are many topics we can discuss, of the sort not
usually covered in ordinary astronomy courses, that arise in the sources you’re observing, processes
alien to everyday experience and, I hope, exciting for their strangeness. Next month we’ll look at a
few other effects of shocks and turbulence, an how these explain some of the things you’re seeing in
spectra. The weather in this time of year is not usu-ally very good, or at least with climate change
it may be worse than in years past, so perhaps con-templating some of physics will cause you to see
stars even on cloudy nights.With warmest wishes from Prague, where I’ll be for
the next few months (under fog, clouds,snow, ... yeah, that sort of weather).
7
Some fluid notions and motionsSteve Shore
ARAS Eruptive Stars Information Letter 2017-01 - p. 39
Some fluid notions and motions - Illustrations for textSteve Shore
ARAS Eruptive Stars Information Letter 2017-01 - p. 40
The Na I D lines in CH Cyg are, for me, among the most interesting developments in this month’s collection. This line is very particular, a doublet resonance tran-sition of a neutral species. There isn’t anything else of that importance in the entire optical spectrum (except for K I but that’s overwhelmed by terrestrial water vapor absorption) and Li I 6707 A, but that’s a very weak line unless the star is quite unusual (you might note that it’s present in the V407 Cyg spec-trum, but that’s an unusual system even for symbiot-ic). So to see a P Cyg absorption means here’s strong excitation of the upper state that can only be by reso-nance line scattering, that the portion of the profile in emission comes from line of sight absorption and then radiative de-excitation of the upper state. For a number of transitions, those from low lying levels such as Fe II, tis isn’t unusual because the absorp-tion occurs in UV multiplets. For sodium, instead, the UV absorption is at around 2500 A. It would be inter-esting to see if any more excited states of Na I show up in the 4500-4700 part of the optical, these are pumped from the UV between 2500-2690 A (there are a number of transitions) where the photons are supplied by the hot star in the system. Little attention has been paid to this (seemingly merely curious) di-agnostic. To produce such emission, since the ioniza-tion potential of neutral Na is rather low (a mere 5.1 eV, low even compared with neutral Fe at 7.9 eV) the region must be well shielded and certainly probes very well the neutral wind. In fact, this is one of the diagnostics that could well indicate the extent of the neutral gas if followed around an orbit. Note, though, that very few systems show the line, in many cases it’s too blended with the absorption from the giant.
SU Lyn also seems to show variability but, in this case, it’s in the absorption column density, not emission. The most interesting observation would probably be a comparison of the 5682.63, 5688.20 A doublet that decays into the upper states of the Na I D dou-blet (5889.95, 5895.92 A the doublet has a common ground state, like Ca II, with the doublet coming from the splitting of the 2Po upper state). The upper state of the excited doublet is fed from ground state absorp-tion at 2893.62 A, so at about the same wavelength as the (strong) Mg II H and K doublet at around 2800 A.Remember that the symbiotics form lines over their entire wind volume so comparing lines of the same el-ement but different excitations and ionization states maps the structure in three dimensions. For example, note where the [O I] 6300 A line sits in velocity as a
function of time relative to [O III] 5959,5007, or where the [N II] 5755 line sits relative to the [O I]. The differ-ences due to electron density are minimal since these are all forbidden transitions, and the ionization maps to space through the velocity (look at which part of the prole in velocity is contributed by which species).For example, you expect that where you see OI you won’t see OIII. Note also that the Balmer lines, although excited states, are populated by the Lyman series and so you are really tracing the combination of ionization/recombination and ra-diative excitation from the ultraviolet Lyman series.All this may seem technical but you are looking at a real analogy of a CAT scan. In this case, instead of spatial resolution, you use the velocity structure of the wind and the changing aspect of the system due to orbital motion to trace out the structure. Why, you might ask, is this important (other than just neat)? If we are ever to understand how mass is accreted in these systems, which significantly al-ters the orbital properties of the binary through mass loss and exchange, and also increases the WD mass and powers the emission spectrum, we have to fol-low the hydrodynamics. Tracking the highest ioniza-tion not the highest temperature gas through, say, [FeVII] 6087, or [Ca V] 5309, tracks gas close to the ionizing source, the mass gaining WD. The neutral species are either within the Balmer recombination region (N and O, for instance) or completely neutral (C, Na). The Ca II lines are another important tracer since they’re, in part, from the giant chromosphere. But in many cases the stars are so faint at this wave-length that it will be difficult to observe the profiles.
As usual, my thanks. These columns are, I know, be-coming more detailed as we go along but I hope they remain understandable and interesting. There are many topics we can discuss, of the sort not usually covered in ordinary astronomy courses, that arise in the sources you’re observing, processes alien to every-day experience and, I hope, exciting for their strange-ness. Next month we’ll look at a few other effects of shocks and turbulence, an how these explain some of the things you’re seeing in spectra. The weather in this time of year is not usually very good, or at least with climate change it may be worse than in years past, so perhaps contemplating some of phys-ics will cause you to see stars even on cloudy nights.With warmest wishes from Prague, where I’ll be for the next few months (under fog, clouds, snow, ... yeah, that sort of weather).
Some comments on the spectra of the month : CH Cyg & SU LynSteve Shore
ARAS Eruptive Stars Information Letter 2017-01 - p. 41
Gamma-ray novae: rare or nearby?Morris, Paul J.; Cotter, Garret; Brown, Anthony M.; Chadwick, Paula M.Monthly Notices of the Royal Astronomical Society, vol. 465, issue 1, pp. 1218-1226http://adsabs.harvard.edu/abs/2017MNRAS.465.1218M
When does an old nova become a dwarf nova? Kinematics and age of the nova shell of the dwarf nova AT CancriShara, Michael M.; Drissen, Laurent; Martin, Thomas; Alarie, Alexandre; Stephenson, F. RichardMonthly Notices of the Royal Astronomical Society, vol. 465, issue 1, pp. 739-745http://adsabs.harvard.edu/abs/2017MNRAS.465..739S
A Comprehensive Observational Analysis of V1324 Sco, the Most Gamma-Ray Luminous Classical Nova to DateFinzell, Thomas; Chomiuk, Laura; Metzger, Brian D.; Walter, Frederick M.; Linford, Justin D.; Mukai, Koji; Nelson, Thomas; Weston, Jennifer H. S.; Zheng, Yong; Sokoloski, Jennifer L.; Mioduszewski, Amy; Rupen, Michael P.; Dong, Subo; Bohlsen, Terry; Buil, Christian; Prieto, Jose; Wagner, R. Mark; Bensby, Thomas; Bond, I. A.; Sumi, T.; Bennett, D. P.; Abe, F.; Koshimoto, N.; Suzuki, D.; P.; Tristram, J.; Christie, Grant W.; Natusch, Tim; McCormick, Jennie; Yee, Jennifer; Gould, Andyhttp://adsabs.harvard.edu/abs/2017arXiv170103094F
The Galactic Nova Rate RevisitedShafter, A. W.The Astrophysical Journal, Volume 834, Issue 2, article id. 196, 11 pp. (2017)http://adsabs.harvard.edu/abs/2017ApJ...834..196S
A Self-Consistent Model for a Full Cycle of Recurrent Novae -- Wind Mass Loss Rate and X-Ray LuminosityKato, Mariko; Saio, Hideyuki; Hachisu, Izumihttp://adsabs.harvard.edu/abs/2017arXiv170101825K
Recent publications
Novae
ARAS Eruptive Stars Information Letter 2017-01 - p. 42
OVI 6830 Å Imaging Polarimetry of Symbiotic StarsAkras, Stavroshttp://adsabs.harvard.edu/abs/2017arXiv170108898A
Reclassifying symbiotic stars with 2MASS and WISE: An atlas of spectral energy distributionAkras, Stavros; Guzman-Ramirez, Lizette; Leal-Ferreira, Marcelo; Ramos-Larios, Gerardohttp://adsabs.harvard.edu/abs/2017arXiv170108894A
Symbiotics
Please :- respect the procedure- check your spectra BEFORE sending themResolution should be at least R = 500For new transcients, supernovae andpoorly observed objects,SA spectra at R = 100 are welcome
1/ reduce your data into BeSS file format2/ name your file with: _ObjectName_yyyymmdd_hhh_Observer Exemple: _chcyg_20130802_886_toto.fit
3/ send you spectra to Novae, Symbiotics, Cataclysmics : François Teyssier
to be included in the ARAS database
Astronomical Ring for Access to Spectroscopy (ARAS) is an infor-mal group of volunteers who aim to promote cooperation between professional and amateur astronomers in the field of spectroscopy.
To this end, ARAS has prepared the following roadmap:
• Identify centers of interest for spectroscopic observa-tion which could lead to useful, effective and motivating co-operation between professional and amateur astronomers.• Help develop the tools required to transform this cooperation into action (i.e. by publishing spectrograph building plans, organizing group purchasing to reduce costs, developing and validating observa-tion protocols, managing a data base, identifying available resourc-es in professional observatories (hardware, observation time), etc.•Develop an awareness and education policy for amateur astrono-mers through training sessions, the organization of pro/am semi-nars, by publishing documents (web pages), managing a forum, etc.• Encourage observers to use the spectrographs available in mission obser-vatories and promote collaboration between experts, particularly variable star experts.• Create a global observation network.
By decoding what light says to us, spectroscopy is the most productive field in astronomy. It is now entering the amateur world, enabling amateurs to open the doors of astrophysics. Why not join us and be one of the pioneers!
Be Monthly reportPrevious issues : http://www.astrosurf.com/aras/surveys/beactu/index.htm
About ARAS initiative
Submit your spectra to ARAS Eruptive Stars Data Base
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