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York University
Faculty of Science
Department of Physics and Astronomy

PHYS 2070 3.0 W14/15
Galaxies and the Universe


 Lecture Notes

6 January  2015
Welcome to the new term and to the course Galaxies and the Universe!

 Please go to www.yorku.ca/prs to register your clicker.

Unfortunately I have to be out of town this first week. Please read Chapter 17 of the book UNIVERSE. Please also
familiarize yourself with the blue lab book "Observational Project."

8 January 2015

13 January 2015
  We started on Ch. 17 and covered material up to p. 469 of  "Universe" 10th edition.

15 January 2015
 At the beginning of class each student was assigned a galaxy for the observing project. Then we  covered material up to  p 486. We calculated the luminosity of the sun from the solar constant. We talked about Wien's law, and the Stefan-Boltzmann constant and figured out how to determine the radius of a star. We started on the HR- diagram. At the end  we had our first quiz. Please be prepared for the Observatory training. Look at the youtube videos. You can search for yorku observatory or go to the links on the phys2070 website.

20 January 2015
 Today we had our observatory training session. The training session is mandatory for anybody of the class to use the telescope.
After the training session we continued with the course. We covered the radius determination and are now on p. 489.

22 January 2015
 We are meeting in LSB 108 (computer lab in Lumbers) to get instructions for using the software package IRAF for the analysis
of the CCD images of the project for the course. Please make sure that you have activated your account on 22 January on cosmos by going to
then find Manage My Services
and click on Activate Cosmos Account

27 January 2015

We learned about how the mass of stars is determined if the stars are members of a binary system. Then we looked at
masses of main sequence stars and the mass to luminosity relation for these stars. We are now on p. 504.

29 January 2015

We started with Chapter 18. We looked at reflection nebula, emission nebula and dark nebulae. We looked at the birth of stars
and followed the birth evolution through tracks in the HR diagram. Jets can emanate from protostars and end in Herbig Haro objects.

3 February 2015

We started with Chapter 19. We talked about the evolution of a cluster, population I and II stars, Cepheids.

5 February 2015

 We talked about close binaries and how each of them affects the evolution of the other. Then we started with chapter 20.
We covered the evolution of stars with masses from 0.4 to 2-3 Msol. Fusion of He, helium flash, horizontal branch, AGB,
planetary nebula, white dwarf, brown dwarf. We are now on p. 575.

10 February 2015
 We covered WDs and supernovae. We learned about SNIa, Ib, Ic and SNII. Do you remember which are core-collapse SNe and
which are thermonuclear detonation SNe?

12 February 2015

 Today we learned about neutron stars, their escape velocity and how they are related to pulsars. All pulsars are NS, but not all NS
are pulsars, only those that we see in the form of pulsed radiation. We are now on p. 602.

24 February 2015
We learned about black holes, special relativity and general relativity. What does it mean if space is bent and warped?

26 February 2015
 We had our midterm exam.

17 March 2015
We talked about the midterm exam. We saw the movie "Testing Einstein's Universe."

19 March 2015
We finished Chapter 21 and are now on p 633.

24 March 2015
We talked about our own Galaxy.

26 March 2015
We finished Chapter 22. In particular we learned about the detection of radio waves from the Galactic Center by Karl Jansky.
We looked at the Galactic Center in the radio and learned about synchrotron radiation. Then we saw an animation of the stars
orbiting our Galaxy's supermassive black hole. We computed the mass of the black hole. Do you remember what the mass is?
We then started on Chapter 23, learned about Hubble and his distance measurement of galaxies with Cepheids and the classification scheme of galaxies. We are now on p 677.

31 March 2015
We learned about the Hubble law, redshift and the expansion of  the Universe.

2 April 2015
Rotation curves of other galaxies also indicate the presence of dark matter.

7 April 2015
 We looked at quasars and active galaxies and learned about superluminal expansion velocities of jets in quasars.

9 April 2015
We learned about the CMB, the evolution of the Universe and that the Universe is accelerating.

14 April 2015
We learned about the amazing theories about the evolution of the Universe from 10-43 s to the present.
Inflation , inflation, inflation... and then the miniscule temperature variations of the CMB leading to our present
cosmic web.

16 April 2015
 We started with finishing Chapter 26. We then focused on habitable zones on the Galaxy and in a region around stars.
Then we looked at communication aspects with hypothetical alients and learned that we have not yet got contact to them.
But who knows what the future will bring??? And that was the end of the course.
See you for the final exam in ACW 005 on 20 April 2015 from 2:00 pm to 5:00 pm.