Episode 294 – Stars You Should Know Show Notes

Focusing on classic Greek-Roman names with occasional indigenous references. The classic names are used in some GoTo telescope software for sky alignment (e.g. Sky-Watcher SynScan and Celestron).

Spectral classes O B A F G K M — Annie Jump Cannon 

References:

Star Tales (2018) Ian Ridpath

Star Names (1963) Richard Hinckley Allen 

Sky Safari 7 Pro (star lore by Jim Kaler)

A Concise Dictionary of Astronomy (1991) Jacqueline MItton 

 

Stars You Should Know—Winter About 12 bright stars 

• all brighter than 2nd magnitude (easy to find, even in the city)
  • all used for celestial navigation (58 in all)

 

Starting with Orion

• not the biggest constellation, but the most prominent
• first constellation Dave learned from his father at age 8 back in 1962
• find other stars and constellations starting from Orion
• all are Sky-Watcher alignment stars and most are Celestron

ORION (Ori)

• Betelgeuse  alpha Ori      “Shoulder”
  • Mag. 0.5 variable star, M2 orange-red supergiant, 20 solar masses 10th brightest star (in night sky), 500 light years
  • 2nd or 3rd largest star in angular diameter (50 mas)—Mira and R Dor larger Famously dimmed in 2019/2020 due to occluding gas cloud ejected from star.

 

• Rigel  beta Ori        “Foot’
  • Mag. 0.2 variable double star, B2 white supergiant, 18–24 solar masses 
  • 7th brightest star, 900 light years
  • Compare with Rigil Kentauris, the “Foot of the Centaur” aka alpha Centauri

 

• Bellatrix      gamma Ori  “Female Warrior”
  • Mag. 1.6, B2 blue-white giant, 8 solar masses

 

• Alnilam        epsilon Ori  “String of Pearls”
  • Mag. 1.7 variable double star, B0 blue-white supergiant, 40–44 solar masses 
  • Middle star of the Belt of Orion: Alnitak-Alnilam-Mintaka
  • “Three Marys” “Three Chiefs Fishing”
  • 1 degree south of the celestial equator
  • From anywhere on Earth, these stars rise due east and set due west

 

• (Saiph)         kappa Ori    Mag. 2.1 CANIS MAJOR (CMa)
  • Sirius alpha CMa   “Scorching”
  • Mag. –1.4 double star, A0 white main sequence, 2 solar masses
  • Follow Belt of Orion down and to the left to find Sirius
  • Brightest star—8.7 light years
  • Closest star visible to the naked eye from mid-northern latitudes
  • “Dog Star”—heliacal rising in August associated with hot “Dog Days of Summer”
  • Bessel noted unusual oscillation in position
  • Alvan Clark discovers white dwarf Sirius B while testing new refractor Sirius—Brightest Diamond in the Sky (2007) Jay B. Holberg

 

• Adhara         epsilon CMa            “The Virgins”
  • Mag. 1.5 double star, B2 blue-white giant, 13 solar masses
  • Adhara is south of Sirius.
  • More luminous than Sirius but 47x more distant (410 light years) 
  • Most luminous star in UV, used to be brighter than Sirius

 

TAURUS (Tau)

 

• Aldebaran   alpha Tau    “The Follower” (follows the Pleiades)
  • Mag. 0.9 variable multiple star, K5 orange giant, 1.2 solar masses
  • Follow Belt of Orion up to the right to find Aldebaran
  • Among the Hyades star cluster but not associated 1.1 solar masses 
  • One of the comparison stars for brightness estimates of Betelgeuse

 

• Elnath           beta Tau       “The Butting One”
  • Mag. 1.7 double star, B7 blue-white giant, 5 solar masses
  • Follow Rigel through Bellatrix and up to find Elnath.
• Once associated with Auriga (many star charts still imply this)

CANIS MINOR (CMi)

• Procyon        alpha CMi    “Before the Dog”
  • Mag. 0.4 variable double star, F5 blue-white main sequence, 1. 5 solar masses
  • Follow Bellatrix through Betelgeuse to the left to find Procyon.
  • 8th brightest star, 11.5 light years GEMINI (Gem)

 

• Pollux           beta Gem     “One of the Twins”
  • Mag. 1.2 variable star, K0 yellow-white giant, 1.9 solar masses
  • Follow Rigel through Betelgeuse to the upper left to find The Twins.

 

• (Castor)        alpha Gem
  • Pollux closest to Procyon, Castor closest to Capella

 

AURIGA (Aur)

• Capella         alpha Aur    “She Goat”
  • Mag. 0.1 variable multiple star, G6 yellow-orange subgiant, 2.6 solar masses
  • Follow Rigel through Bellatrix and Elnath to find Auriga.
  • 6th brightest star

• (Elnath)       beta Tau—also used to be gamma Auriga “Foot of the Charioteer”

 

WINTER ASTERISMS

Winter Triangle    Betelgeuse–Procyon–Sirius–Betelgeuse

Winter Hexagon   Capella–Pollux–Procyon–Sirius–Rigel–Aldebaran–Capella

Winter “G”   Capella–Pollux–Procyon–Sirius–Rigel–Aldebaran–Betelguese

References:

• Star Tales (2018) Ian Ridpath
• Star Names (1963) Richard Hinckley Allen 
• Sky Safari 7 Pro (star lore by Jim Kaler)
• A Concise Dictionary of Astronomy (1991) Jacqueline MItton