galactic coordinates - astronomy groupstar-spd3/teaching/as2001gal/galactic... · 2010. 9. 29. ·...
TRANSCRIPT
![Page 1: Galactic coordinates - ASTRONOMY GROUPstar-spd3/Teaching/AS2001Gal/galactic... · 2010. 9. 29. · Use Cosine rule twice and sine rule once to solve independently for l & b = = see](https://reader035.vdocuments.site/reader035/viewer/2022062510/61151ae786925203f24befdd/html5/thumbnails/1.jpg)
AS 2001 Galactic Astronomy
Galactic coordinates
• α : Right ascension l : Galactic longitude • δ : Declenation b : Galactic latitude
• How do we transfer between coordinate systems?
NCP NGP
Equatorial Galactic
celestial equator α
δ
Galactic equator
b l GC
Motivated by Earth’s rotation
Motivated by Galactic rotation
![Page 2: Galactic coordinates - ASTRONOMY GROUPstar-spd3/Teaching/AS2001Gal/galactic... · 2010. 9. 29. · Use Cosine rule twice and sine rule once to solve independently for l & b = = see](https://reader035.vdocuments.site/reader035/viewer/2022062510/61151ae786925203f24befdd/html5/thumbnails/2.jpg)
AS 2001 Galactic Astronomy
Galactic latitude, l
![Page 3: Galactic coordinates - ASTRONOMY GROUPstar-spd3/Teaching/AS2001Gal/galactic... · 2010. 9. 29. · Use Cosine rule twice and sine rule once to solve independently for l & b = = see](https://reader035.vdocuments.site/reader035/viewer/2022062510/61151ae786925203f24befdd/html5/thumbnails/3.jpg)
AS 2001 Galactic Astronomy
Galactic Longitude l=0=Gal. centre
Galactic Latitude b=0=in plane
b & l
![Page 4: Galactic coordinates - ASTRONOMY GROUPstar-spd3/Teaching/AS2001Gal/galactic... · 2010. 9. 29. · Use Cosine rule twice and sine rule once to solve independently for l & b = = see](https://reader035.vdocuments.site/reader035/viewer/2022062510/61151ae786925203f24befdd/html5/thumbnails/4.jpg)
AS 2001 Galactic Astronomy
![Page 5: Galactic coordinates - ASTRONOMY GROUPstar-spd3/Teaching/AS2001Gal/galactic... · 2010. 9. 29. · Use Cosine rule twice and sine rule once to solve independently for l & b = = see](https://reader035.vdocuments.site/reader035/viewer/2022062510/61151ae786925203f24befdd/html5/thumbnails/5.jpg)
AS 2001 Galactic Astronomy
![Page 6: Galactic coordinates - ASTRONOMY GROUPstar-spd3/Teaching/AS2001Gal/galactic... · 2010. 9. 29. · Use Cosine rule twice and sine rule once to solve independently for l & b = = see](https://reader035.vdocuments.site/reader035/viewer/2022062510/61151ae786925203f24befdd/html5/thumbnails/6.jpg)
AS 2001 Galactic Astronomy
Cosine/sine rules of spherical trig.
cos(c)=cos(a).cos(b)+sin(a).sin(b).cos(C)
sin(a) sin(b) sin(c) sin(A) sin(B) sin(c)
Use Cosine rule twice and sine rule once to solve independently for l & b
= =
see over…
![Page 7: Galactic coordinates - ASTRONOMY GROUPstar-spd3/Teaching/AS2001Gal/galactic... · 2010. 9. 29. · Use Cosine rule twice and sine rule once to solve independently for l & b = = see](https://reader035.vdocuments.site/reader035/viewer/2022062510/61151ae786925203f24befdd/html5/thumbnails/7.jpg)
AS 2001 Galactic Astronomy
![Page 8: Galactic coordinates - ASTRONOMY GROUPstar-spd3/Teaching/AS2001Gal/galactic... · 2010. 9. 29. · Use Cosine rule twice and sine rule once to solve independently for l & b = = see](https://reader035.vdocuments.site/reader035/viewer/2022062510/61151ae786925203f24befdd/html5/thumbnails/8.jpg)
AS 2001 Galactic Astronomy
![Page 9: Galactic coordinates - ASTRONOMY GROUPstar-spd3/Teaching/AS2001Gal/galactic... · 2010. 9. 29. · Use Cosine rule twice and sine rule once to solve independently for l & b = = see](https://reader035.vdocuments.site/reader035/viewer/2022062510/61151ae786925203f24befdd/html5/thumbnails/9.jpg)
AS 2001 Galactic Astronomy
Examples
• See Q 2 of tutorial sheet 1
or compare to:
• http://nedwww.ipac.caltech.edu/forms/calculator.html