Class Notes (838,343)
Canada (510,861)
Astronomy (103)
ASTA02H3 (22)
Lecture

Astronomy - Session 2

4 Pages
174 Views
Unlock Document

Department
Astronomy
Course
ASTA02H3
Professor
Parandis Khavari
Semester
Winter

Description
Astronomy - Session 2  apparent visual magnitude  describes how stars look to human eyes  apparent magnitude  the brightness of stars is measured using the magnitude scale  ancient astronomers divided the stars into six magnitudes  m =vapparent visual magnitude  a star may have negative or positive magnitude  Q. what is the name of the star that serves as the zero of the magnitude scale?  A. Vega  Q. what is brighter, a -1 star or a +3.5 star?  A. a -1 m vtar is brighter than a +3.5  12,000 BC  Vega was the northern star  distance is measured through ground-based parallax measurements  its spectrum was amongst the first to be measured  Q. the m ov a number of stars is given- sort them in order of descending brightness  a) Proxinma Centauri, +11.05  b) Betelgeuse, 0.42  c) Antares, +0.96  d) Dubje, +1.79  e) Sirius A, -1.46  f) Sirius B, +8.49  A. e), b), c), d), f), a)  distance and luminosity  two factors in determining m v  absolute magnitude  also known as "intrinsic brightness"  luminosity  total electromagnetic output of energy per unit of time  seconds  most convenient way to do measurement of time in astronomy  flux (F)  apparent magnitude is a function of flux  measurement of the received energy  defined as the energy (measured in Joules) per second per one square meter  by definition obeys the Inverse Square Law  directly proportional to luminosity  F ↔ ( d/s/m 2  watt= d /s  absolute magnitude  not a reliable measure for the true brightness of a star  true measurement for the intrinsic brightness of the stars is called absolute magnitude  definition as the apparent magnitude of all stars if they were moved to a distance 10 parsecs (33 light years) from the Earth  converting absolute magnitude to apparent m
More Less

Related notes for ASTA02H3

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit