Concerning the Stars

A G2 V star that most of us are rather familiar with: the Sun.


Without our local star of the Sun, life on Earth as we know it would not be possible.  In the midst of the cold snap in the Eastern United States, we might appreciate all the more the warming action of the Sun.  In fact, on 2 January, we reached our Aphelion, our closest point to the Sun on our orbit -- it is too bad for us in the Northern Hemisphere that we are tipped away from the Sun at this point!

Yet, these crisp nights also allow us to view a particularly clear night sky, and the winter constellation present to us some of the brightest and most impressive stars, from our perspective.

Below I have compiled a list of the brightest stars visible in the skies of the northern latitudes, including their common name, Bayer designation, their Spectral Type (which classifies stars based on their surface temperature, along with the Roman Numeral indicating the luminosity class, whereby the lower the Roman number the more massive the star) and finally its apparent magnitude, or brightness as it appears to us.  Below that, I have a list of the closests stars to us, along with a chart presenting a list of the different spectral classes.

It is a delightful exercise to try to detect the color of the brighter stars -- with Rigel and Betelguese in Orion being a wonderful exercise and comparison.

So, let us enjoy the stars and clear nights of winter, even if we wish for a bit more of the warmth of the sun!

Brightest Stars of the Northern Sky

           

NAME                   DESIGNATION                  SPECTRAL TYPE                 MAGNITUDE

SUN	---	G2 V	-26.75
SIRIUS	α Canis Majoris	A1 V	-1.45
ARCTURUS	α Boötis	K2 III	-0.04
VEGA	α Lyrae	A0 V	0.03
CAPELLA	α Aurigae	G6 III & G2 II	0.08
RIGEL	β Orionis	B8 Ia	0.12
PROCYON	α Canis Minoris	F5 IV-V	0.4
BETELGEUSE	α Orionis	M2 Iab	0.7 (Variable)
ALTAIR	α Aquilae	A7 V	0.77
ALDEBARAN	α Tauri	K5 III	0.85
ANTARES	α Scorpii	M1 Ib	0.92 (Variable)
SPICA	α Virginis	B1 V	1.00 (Variable)
POLLUX	β Geminorum	K0 III	1.14

NEXT FOUR: Fomalhaut (Piscis Austrinus), Deneb (Cygnus), Regulus (Leo), Adhara (Canis Major)

NB: This excludes the bright southern stars, which would number #3, 4, 10, 11, 15, 21.

Closest Stars to Earth

STAR                                                     LIGHT YEARS DISTANT                APPARENT MAGNITUDE

1. Sun                                                  8 light minutes                        -26.75

2. Proxima Centauri                            4.21                                         11.05

3. Alpha Centauri [Binary]                 4.37                                         0.02

4. Barnard’s Star (Ophiuchus)            5.94                                         9.54

5. Wolf 359 (Leo)                               7.80                                         13.45

6. Lalande 21185 (Ursa Maj.)           8.32                                         7.49

7. Luyten 726-8 [Binary] (Cetus)        8.5                                           12.3

8. Sirius [Binary]                                 8.61                                         -1.45

Spectral Types and Star Classification

Surface Temperature Ranges for Different Stellar Classes
Class	Temperature	Sample stars
O	33,000 K or more	ζ [Zeta] Ophiuchi, δ [Delta] Orionis (Mintaka)
B	10,500–30,000 K	Rigel, Spica, the Pleiades
A	7,500–10,000 K	Altair, Vega, Deneb, Sirius
F	6,000–7,200 K	Procyon A, Polaris
G	5,500–6,000 K	Sun, Capella
K	4,000–5,250 K	Arcturus, Aldebaran
M	2,600–3,850 K	Betelgeuse, Antares, Barnard’s Star

Live well!