Notes
Slide Show
Outline
1
Night Sky : Gemini
  • SMAS March 04 Meeting
2
Legend of Gemini
  • “Twins” concept dates back 6,000 years to India and the “Twin Horsemen of the Dawn” (Spring equinox).
  • Ancient Romans referred to this constellation as the "Twin Brethren" and associated it with the principle of brotherhood.
  • Best known legend is from Greek mythology.
  • Recall Cygnus and the story of Zeus and Leda where Zeus disguised himself as a beautiful swan in order to seduce her.
  • From that union was born Helen of Troy and Pollux.
  • Castor was the mortal son of Leda's husband, Tyndareus, King of Sparta.
3
Legend of Gemini
  • Castor and Pollux were also Argonauts, being among the crew who sailed with Jason in the Quest for the Golden Fleece.
  • During the voyage a storm abated when two stars appeared above the heads of Castor and Pollux – hence, since considered protectors of sailors.
    • Apostle Paul sailed from the Isle of Melita during his journey to Rome on a ship adorned with Castor and Pollux figureheads.
  • The twins slew Idas and Lynceus in battle for the daughters of Leudippus – Castor was mortally wounded.
  • Pollux was so distraught that Zeus placed them together in the sky as symbols of brotherly love.


4
M35 and Surrounding Region
  • Rich area of the Milky Way dense with stars and nebula
  • Excellent viewing with binoculars or RFT
5
M35
  • Large cluster – one of the finest
  • Size: 28.0'
    Mag: 5.1
    Brightest star: 8.2
    Number of stars: 200
  • Superb binocular object
  • Look for NGC 2158 ˝ degree southwest of M35
  • NGC 2158 is six times more distant
6
NGC 2129
  • Open cluster about 2° west of M35
  • Size: 7.0'
    Mag: 6.7
    Brightest star: 7.4
    Number of stars: 40
  • Try using 100x under a dark sky to glimpse the fainter members



7
NGC 2175
  • Cluster and associated nebula located in Orion (neighborhood of M35)
  • Size: 18.0'
    Mag: 6.8
    Brightest star: 7.6
    Number of stars: 60
  • Try UHC filter in RFT and 8-inch or larger scopes


8
IC 443
  • Also know as the Jellyfish Nebula
  • Use larger scopes and an O-III filter to observe the brighter NE edge under a very dark sky
  • Supernova remnant
    Distance: 5,000 ly
    Estimated age: 35,000 years
  • Contains a neutron star (Chandra and VLA data)
9
IC 443 and Hydrogen Clouds
  • Beautiful H-alpha shot by John Gleason
10
NGC 2266
  • Compact, dense open cluster
  • Size: 7.0'
    Mag: 9.5
    Brightest star: 11.0
    Number of stars: 50
  • Nice view with
    8-inch and larger scopes under a dark sky
  • Look for star chains


11
NGC 2371-2
  • Double-lobed planetary nebula
  • Size: 1.2' x 0.9'
    Mag: 13.0
    Central star: 14.8
  • Use up to 200x with larger aperture scopes
  • O-III enhances contrast
  • Observed at TAO in
    12.5-inch
12
NGC 2420
  • Another compact, dense open cluster
  • Size: 10.0'
    Mag: 8.3
    Brightest star: 11.1
    Number of stars: 100
  • Almost globular appearance due to background haze of faint stars


13
NGC 2392 Eskimo Nebula
  • Bright planetary, excellent object for all scopes
  • Size: 47.0" x 43.0"
    Mag: 8.6
    Central star: 10.6
  • Central star easily visible
  • O-III filter not necessary
  • Use higher powers to resolve shell structure if seeing allows
14
 
15
NGC 2355-6
  • YACDOC (Yet another compact, dense open cluster)
  • Size: 9.0'
    Mag: 9.7
    Brightest star: 13.0
    Number of stars: 40
  • Needs a larger scope for impact, but seemingly easy to find


16
Challenging Objects
  • “Medusa Nebula” PK 205+14.1
  • Find cluster NGC 2395 and then move SE about ˝ degree
  • Observed at TAO with wide-field EP and O-III filter in 12.5-inch
  • Mag: 14.1
    Size: 10.0' x 6.0'


17
Challenging Objects
  • NGC 2339
    Spiral Galaxy
  • Magnitude: 12.5
    Surface brightness: 13.1 mag/sq arcmin
    Size: 2.7' x 2.0'
  • Larger scope and dark sky obviously required



18
Double Stars in Gemini