Objects for November-December

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)