TAAS Observing Challenge February 2016 Deep Sky Object NGC 2775 (GX) Cancer ra: 09h 10m 20.4s dec: +07° 02’ 13” Magnitude (visual) = 10.1 Size = 4.3’ x 3.3’ Position angle = 155° Distance = approximately 55.5 million light years Description: NGC 2775 (also known as Caldwell 48) is a spiral galaxy in the constellation Cancer. This galaxy has a bulge and multiple spiral arms, on which few HII regions can be detected, implying recent star formation. It was discovered by William Herschel in 1783. NGC 2775 is the most prominent galaxy in a small galaxy group known as NGC 2775 group, part of the Virgo Supercluster, along with the Local Group. Other members of the NGC 2775 group include NGC 2777 and UGC 4781.[2] Source: https://en.wikipedia.org/wiki/NGC_2775 AL: Herschel 400, Caldwell [48] Challenge Object NGC 3655 (GX) Leo ra: 11h 22m 54.6s dec: +16° 35’ 20” Magnitude (visual) = 11.7 Size = 1.5’ x 1.0’ Position angle = 30° Description: A small, fuzzy patch. Very faint. Galaxy type SA(s)c : III-IV. AL: Herschel 400 Binocular Object Eta Canis Majoris (DS) Canis Major (aka Aludra) ra: 07h 24m 05.7s dec: -29° 18’ 11.18” Magnitudes (visual) = 2.4, 6.9 Separation = 178.7” Position angle = 285° Distance = approximately 2000 light years Description: Eta Canis Majoris (η CMa, η Canis Majoris) is a star in the constellation Canis Major. It has the traditional name Aludra. Since 1943, the spectrum of this star has served as one of the stable anchor points by which other stars are classified. Aludra shines brightly in the skies in spite of a large distance from Earth due to being intrinsically many times brighter (absolute magnitude) than the Sun. A blue-white supergiant of spectral type B5Ia, Aludra has a luminosity 176,000 times and a diameter around 80 times that of the Sun. Hohle and colleagues, using the parallax, extinction and analysis of spectrum, came up with a mass 19.19 times that and luminosity 105,442 times that of the Sun. It has only been around a fraction of the time our Sun has, yet is already in the last stages of its life. It is still expanding and may become a red supergiant, or perhaps has already passed that phase, but in either case it will become a supernova within the next few million years. Aludra is classified as an Alpha Cygni type variable star and its brightness varies from magnitude +2.38 to +2.48 over a period of 4.7 days. Source: https://en.wikipedia.org/wili/Eta_Canis_Majoris AL: Binocular Double Star Double Star Gamma Ceti (DS) Cetus ra: 02h 43m 18s dec: +03° 14’ 09.8” Magnitudes (visual) = 3.5, 7.3 Separation = 2.8” Position angle = 294° Distance = approximately 70 light years Description: Gamma Ceti appears to be a triple star system. The inner pair have an angular separation of 2.6 arcseconds. The primary component of this pair is a visual magnitude 3.6, A-type main sequence star with a stellar classification of A3 V. The fainter secondary component is an F-type main sequence star that has a classification of F3 V and a magnitude of 6.6. The contrasting colors of these two stars make them a popular target of amateur astronomers. The two can be resolved with a small, 4 inch (10 cm) aperture telescope under ideal seeing conditions, although at times they are can be a challenge to resolve even with a much larger scope. At a wide separation of 840 arcseconds is a dim, magnitude 10.2 K- type star with a classification of K5. The luminosity class of this last component remains undetermined. At the estimated distance of this system, this yields a physical size of about 1.9 times the radius of the Sun. The secondary component of this system is an X-ray source with a luminosity of 2.2 × 1029 erg s−1. Gamma Ceti is about 300 million years old and it appears to be a member of the stream of stars loosely associated with the Ursa Major moving group. The primary has been examined for an excess of infrared emission that would suggest the presence of circumstellar matter, but none was found. Source: http://en.wikipedia.org/wiki/ AL: Double Star .