supernovae historically: “new stars” in sky seen in 1006, 1054, 1181, 1572, 1604, 1680 sn 1054...
Post on 21-Dec-2015
217 views
TRANSCRIPT
![Page 1: Supernovae Historically: “new stars” in sky Seen in 1006, 1054, 1181, 1572, 1604, 1680 SN 1054 visible in daytime sky for many months (Chinese records)](https://reader035.vdocuments.site/reader035/viewer/2022070323/56649d635503460f94a45959/html5/thumbnails/1.jpg)
Supernovae
• Historically: “new stars” in sky
• Seen in 1006, 1054, 1181, 1572, 1604, 1680
• SN 1054 visible in daytime sky for many months (Chinese records)
• SN 1572 – Tycho, SN 1604 – Kepler
• SN 1987A is the only SN visible to the naked eye since the development of telescopes. It is in the Large Magellanic Cloud (50 kpc distant)
![Page 2: Supernovae Historically: “new stars” in sky Seen in 1006, 1054, 1181, 1572, 1604, 1680 SN 1054 visible in daytime sky for many months (Chinese records)](https://reader035.vdocuments.site/reader035/viewer/2022070323/56649d635503460f94a45959/html5/thumbnails/2.jpg)
Tycho’s report on his observations of the SN of 1572
![Page 3: Supernovae Historically: “new stars” in sky Seen in 1006, 1054, 1181, 1572, 1604, 1680 SN 1054 visible in daytime sky for many months (Chinese records)](https://reader035.vdocuments.site/reader035/viewer/2022070323/56649d635503460f94a45959/html5/thumbnails/3.jpg)
![Page 4: Supernovae Historically: “new stars” in sky Seen in 1006, 1054, 1181, 1572, 1604, 1680 SN 1054 visible in daytime sky for many months (Chinese records)](https://reader035.vdocuments.site/reader035/viewer/2022070323/56649d635503460f94a45959/html5/thumbnails/4.jpg)
Supernovae
• Historically: “new stars” in sky
• Seen in 1006, 1054, 1181, 1572, 1604, 1680
• SN 1054 visible in daytime sky for many months (Chinese records)
• SN 1572 – Tycho, SN 1604 – Kepler
• SN 1987A is the only SN visible to the naked eye since the development of telescopes. It is in the Large Magellanic Cloud (50 kpc distant)
![Page 5: Supernovae Historically: “new stars” in sky Seen in 1006, 1054, 1181, 1572, 1604, 1680 SN 1054 visible in daytime sky for many months (Chinese records)](https://reader035.vdocuments.site/reader035/viewer/2022070323/56649d635503460f94a45959/html5/thumbnails/5.jpg)
Most of what we know today about SN comes from studying them in other galaxies.
![Page 6: Supernovae Historically: “new stars” in sky Seen in 1006, 1054, 1181, 1572, 1604, 1680 SN 1054 visible in daytime sky for many months (Chinese records)](https://reader035.vdocuments.site/reader035/viewer/2022070323/56649d635503460f94a45959/html5/thumbnails/6.jpg)
![Page 7: Supernovae Historically: “new stars” in sky Seen in 1006, 1054, 1181, 1572, 1604, 1680 SN 1054 visible in daytime sky for many months (Chinese records)](https://reader035.vdocuments.site/reader035/viewer/2022070323/56649d635503460f94a45959/html5/thumbnails/7.jpg)
Why are SNe important?
• The source of most heavy (> He) in the universe.
• Input a lot of mechanical energy into the interstellar medium (1051 erg).
• A laboratory for studying physics under extreme conditions.
• Associated with useful/interesting phenomena: neutron stars and pulsars; SN Ia used in cosmology; SN II associated with gamma ray bursts.
![Page 8: Supernovae Historically: “new stars” in sky Seen in 1006, 1054, 1181, 1572, 1604, 1680 SN 1054 visible in daytime sky for many months (Chinese records)](https://reader035.vdocuments.site/reader035/viewer/2022070323/56649d635503460f94a45959/html5/thumbnails/8.jpg)
Supernovae are energetic explosions
• Rapid rise (10 days) to peak luminosities of about 1010 solar luminosities.
• Spectra show broad, blue-shifted absorption lines with velocities of about 104 km/s.
• Luminous stellar progenitor seen in a few cases.
![Page 9: Supernovae Historically: “new stars” in sky Seen in 1006, 1054, 1181, 1572, 1604, 1680 SN 1054 visible in daytime sky for many months (Chinese records)](https://reader035.vdocuments.site/reader035/viewer/2022070323/56649d635503460f94a45959/html5/thumbnails/9.jpg)
![Page 10: Supernovae Historically: “new stars” in sky Seen in 1006, 1054, 1181, 1572, 1604, 1680 SN 1054 visible in daytime sky for many months (Chinese records)](https://reader035.vdocuments.site/reader035/viewer/2022070323/56649d635503460f94a45959/html5/thumbnails/10.jpg)
SNe Types
• Type Ia: no hydrogen in spectrum, brightest peak luminosity, seen only in both elliptical and spiral galaxies.
• Type Ib/Ic: no hydrogen in spectrum, fainter peak L, seen only in spiral galaxies.
• Type II: hydrogen seen in spectrum, fainter than Ia’s, seen only in spiral galaxies. Light curve (brightness vs time) comes in two broad types – linear (II L) and plateau (II P); though there is a wide diversity in this class.
![Page 11: Supernovae Historically: “new stars” in sky Seen in 1006, 1054, 1181, 1572, 1604, 1680 SN 1054 visible in daytime sky for many months (Chinese records)](https://reader035.vdocuments.site/reader035/viewer/2022070323/56649d635503460f94a45959/html5/thumbnails/11.jpg)
SN spectra at early times: broad absorption lines, some with PCygni profiles.
![Page 12: Supernovae Historically: “new stars” in sky Seen in 1006, 1054, 1181, 1572, 1604, 1680 SN 1054 visible in daytime sky for many months (Chinese records)](https://reader035.vdocuments.site/reader035/viewer/2022070323/56649d635503460f94a45959/html5/thumbnails/12.jpg)
![Page 13: Supernovae Historically: “new stars” in sky Seen in 1006, 1054, 1181, 1572, 1604, 1680 SN 1054 visible in daytime sky for many months (Chinese records)](https://reader035.vdocuments.site/reader035/viewer/2022070323/56649d635503460f94a45959/html5/thumbnails/13.jpg)
![Page 14: Supernovae Historically: “new stars” in sky Seen in 1006, 1054, 1181, 1572, 1604, 1680 SN 1054 visible in daytime sky for many months (Chinese records)](https://reader035.vdocuments.site/reader035/viewer/2022070323/56649d635503460f94a45959/html5/thumbnails/14.jpg)
SNe spectra at late times become dominated by emission lines (hot, low-density gas) of Fe/Co (Type Ia) or light and intermediate elements (Type II and Ib/c)
![Page 15: Supernovae Historically: “new stars” in sky Seen in 1006, 1054, 1181, 1572, 1604, 1680 SN 1054 visible in daytime sky for many months (Chinese records)](https://reader035.vdocuments.site/reader035/viewer/2022070323/56649d635503460f94a45959/html5/thumbnails/15.jpg)
SNe Types
• Type Ia: no hydrogen in spectrum, brightest peak luminosity, seen only in both elliptical and spiral galaxies.
• Type Ib/Ic: no hydrogen in spectrum, fainter peak L, seen only in spiral galaxies.
• Type II: hydrogen seen in spectrum, fainter than Ia’s, seen only in spiral galaxies. Light curve (brightness vs time) comes in two broad types – linear (II L) and plateau (II P); though there is a wide diversity in this class.
![Page 16: Supernovae Historically: “new stars” in sky Seen in 1006, 1054, 1181, 1572, 1604, 1680 SN 1054 visible in daytime sky for many months (Chinese records)](https://reader035.vdocuments.site/reader035/viewer/2022070323/56649d635503460f94a45959/html5/thumbnails/16.jpg)
Sne Light Curves
![Page 17: Supernovae Historically: “new stars” in sky Seen in 1006, 1054, 1181, 1572, 1604, 1680 SN 1054 visible in daytime sky for many months (Chinese records)](https://reader035.vdocuments.site/reader035/viewer/2022070323/56649d635503460f94a45959/html5/thumbnails/17.jpg)
Supernovae searches & rates• Used to be found by dedicated amateurs, today
mostly found by automated surveys (of nearby galaxies) and scheduled discovery campaigns (for distant galaxies).
• Type Ia: one every 300 years in the Milky Way Galaxy (a typical big galaxy).
• Type Ib/c, II: one every 30-50 years in the Milky Way.
![Page 18: Supernovae Historically: “new stars” in sky Seen in 1006, 1054, 1181, 1572, 1604, 1680 SN 1054 visible in daytime sky for many months (Chinese records)](https://reader035.vdocuments.site/reader035/viewer/2022070323/56649d635503460f94a45959/html5/thumbnails/18.jpg)
Berkeley Automated Telescopes
• KAIT: 0.76m automated telescope
• Images about 1000 galaxies a night out to a distance of about 200 Mpc
• Discovers about 80 SNe a year.
![Page 19: Supernovae Historically: “new stars” in sky Seen in 1006, 1054, 1181, 1572, 1604, 1680 SN 1054 visible in daytime sky for many months (Chinese records)](https://reader035.vdocuments.site/reader035/viewer/2022070323/56649d635503460f94a45959/html5/thumbnails/19.jpg)
SN 2008I
![Page 20: Supernovae Historically: “new stars” in sky Seen in 1006, 1054, 1181, 1572, 1604, 1680 SN 1054 visible in daytime sky for many months (Chinese records)](https://reader035.vdocuments.site/reader035/viewer/2022070323/56649d635503460f94a45959/html5/thumbnails/20.jpg)
SN Ia Phillips relation
• Peak brightness is related to the initial rate of decline of the light curve (faster decline goes with a fainter peak).
• More generally, the peak brightness correlates with the shape and color of the light curve.
• Reduces the scatter from 0.4 – 0.5 magnitude to 0.12 – 0.15 mag.