Class Notes (1,100,000)
CA (650,000)
UTSC (30,000)
Astronomy (100)
Lecture

ASTA02H3 Lecture Notes - Photon, Black-Body Radiation, Sirius


Department
Astronomy
Course Code
ASTA02H3
Professor
Parandis Khavari

This preview shows page 1. to view the full 4 pages of the document.
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
mv= apparent 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 mv star 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 mv of 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
You're Reading a Preview

Unlock to view full version