Objects compiled by Alan Gould for 2022 Nov 29 Stargazing at El Cerrito High School
Double Stars
(colors, separation in seconds of arc, orbit period, distance)
γ (gamma) Andromedae (orange-blue, 9.8”, 4,748 yr, 390 ly)
Mizar (14.4”, 83 ly, thousands of yrs period, spectroscopic binaries, + Alcor)
η (eta) Cassiopeiae (yellow-orange, 12”, 480 yr, 19 ly)
Albireo β (beta) Cygni (blue-gold, 34.4”, >100,000yrs??, 420 ly)
ε (epsilon) Lyrae (double double, 208”, 2.6”, 1800 yrs, 2.3”, 720 years)
Open Clusters
(distance in light years, number of stars, age in millions of years)
M 34 Perseus (1500 ly, 400 stars, 200-250 Myrs old)
M 36 Auriga (4300 ly, ~200 stars, 25 Myr old)
M 37 Auriga (4500 ly, >500 stars, 350-550 Myrs old)
M 38 Auriga (3480 ly, ~100 stars, 290 Myrs old)
M 39 Cygnus (1000 ly, a few dozen stars, 230 solar masses, 280 Myrs old)
NGC 869 & 884 Double Cluster in Perseus (7600 ly, 14 Myrs old)
Planetary Nebulae
(distance in light years, diameter in light years)
M57 Ring Nebula 4100 ly ~2.6 ly dia
Helix Nebula in Aquarius NGC 7293 650 ly ~6 ly dia
M27 Dumbbell Nebula in Vulpecula 1360 ly ~3 ly dia
Emission/Diffuse Nebulae
(distance in light years, diameter in light years)
M1 Crab Nebula Taurus, 6500 ly, ~11 ly dia, 1054 AD SN, pulsar 18 mi dia
M42 Orion 1300 ly, ~24 ly dia
Globular Clusters
(distance in light years, number of stars, diameter in light years)
M15 Pegasus 30K ly, >100K stars, ~170 ly dia, central black hole?, x-ray source
M2 Aquarius 55,000 ly, ~150,000 stars, ~175 ly dia, 13 billion years old
Galaxies
(distance in light years, diameter in light years, number of stars)
M31 Andromedae (2.5 Mly, 300K ly dia, ~1 trillion stars, collision in ~5 billion yrs)
M33 Triangulum (3.2 Mly, 61,000 ly dia, ~40 billion stars)
M81 UMa (12 Mly, 96K ly dia, ~200 globular clusters, 70M suns black hole)
NGC 253 Sculptor (cigar, 11.4 Mly, 90,000 ly dia, 5M suns black hole)