Notes

Slide Show

Outline

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2	The space between the stars is not completely empty, but filled with very dilute gas and dust, producing some of the most beautiful objects in the sky.
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4	Three kinds of nebulae
5	2) Reflection Nebulae
6	Emission and Reflection Nebulae
7	3) Dark Nebulae
8	Interstellar Reddening
9	Interstellar Absorption Lines
10	Structure of the ISM HI clouds:
11	The Various Components of the Interstellar Medium
12	Shocks Triggering Star Formation
13	The Contraction of a Protostar
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15	Evidence of Star Formation
16	Protostellar Disks and Jets – Herbig-Haro Objects
17	Protostellar Disks and Jets – Herbig-Haro Objects (II)
18	Herbig-Haro 34 in Orion Jet along the axis visible as red Lobes at each end where jets run into surrounding gas clouds
19	Motion of Herbig-Haro 34 in Orion Can actually see the knots in the jet move with time In time jets, UV photons, supernova, will disrupt the stellar nursery
20	Globules
21	Globules
22	The Source of Stellar Energy
23	The CNO Cycle
24	Fusion into Heavier Elements
25	Hydrostatic Equilibrium
26	Hydrostatic Equilibrium (II)
27	Energy Transport
28	Stellar Structure
29	Stellar Models
30	Interactions of Stars and their Environment
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32	Mass-Luminosity relationship L µ M^3.5Why? Higher mass means higher internal pressure Higher pressure goes with higher temperature Higher temperature means heat leaks out faster Star shrinks until T inside is high enough for fusion rate (which is very sensitive to temperature) to balance heat leak rate
33	Lifetime on Main Sequence L µ M^3.5T µ fuel / L = M/M^{3.5 =} M^-2.5 Example: M=2 M_Sun L = 11.3 L_SunT =1/5.7 T_Sun
34	How about a 0.5 solar mass star? M = 0.5 M_sun Time = Luminosity =
35	How about a 0.5 solar mass star? M = 0.5 M_sun Time = 5.7 times solar lifetime Luminosity = 0.09 solar luminosity
36	The Orion Nebula: An Active Star-Forming Region
37	Orion Nebula: A Star-Forming Region Red light = Hydrogen emission Blue light = reflection nebula Dark lanes = dust Astronomy Picture of the Day: http://antwrp.gsfc.nasa.gov/apod
38	The Trapezium
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40	Protoplanetary Disks in the Orion Nebula Dusty disk seen in silhouette Central star visible at long wavelengths