NGC 2775 is a magnitude +10.5 spiral galaxy located in the constellation of Cancer, close to its border with Hydra. This galaxy is unusual in that it contains a very smooth nucleus with multiple spiral arms extending outwards from the central region. What makes the spiral arms interesting are their incredible complex detail, tightly wound structures and active star formation. Amateur astronomers should also keep their eye on this galaxy; it's been host to 5 supernovae explosions in the past 30 years and you never know when the next one will go off!
To find NGC 2775 look for the head of Hydra "the Sea Serpent". The asterism of stars that forms the head are ω Hyd (mag. +5.0), ζ Hyd (mag. +3.1), ρ Hyd (mag. +4.4), ε Hyd (mag. +3.4), δ Hyd (mag. +4.1), σ Hyd (mag. +4.5) and η Hyd (mag. +4.3). None of these stars are particularly bright, but all can be seen with the naked eye. The galaxy is positioned a few degrees east and slightly north of this grouping.
NGC 2775 was discovered by William Herschel in 1783 and is best seen during the months of February, March and April. The galaxy is located 55.5 million light-years from Earth and has an actual diameter of 70,000 light-years. It's estimated to contain 100 billion stars. NGC 2775 is number 48 in the Caldwell catalogue.
Finder Chart for NGC 2775 - pdf format (credit:- freestarcharts)
NGC 775 can be seen with telescopes of 100mm (4-inch) aperture on dark nights with good transparency. At best it appears as very dim glow of light. The galaxy appears as a nebulous pale streak of light in a 200mm (8 inch) scope at about 120x magnification. Larger 300mm (12-inch) instruments reveal a large and bright oval shaped galaxy with a bright core and some fine mottling in the arms. The beauty of the tightly wound spiral arms is revealed in images taken by the finest telescopes, such as the Hubble Space Telescope. Overall NGC 775 spans 4.3 x 3.3 arc minutes of apparent sky.
It is the largest galaxy in a small group known as NGC 2775 group and forms part of the Virgo Supercluster that also includes NGC 2777 and UGC 4781.
NGC 2775 Data Table
NGC | 2775 |
---|---|
Caldwell | 48 |
Object Type | Spiral Galaxy |
Constellation | Cancer |
Distance (light-years) | 55.5 Million |
Apparent Mag. | +10.5 |
RA (J2000) | 09h 10m 20s |
DEC (J2000) | 07h 02m 16s |
Apparent Size (arc mins) | 4.3 x 3.3 |
Radius (light-years) | 35,000 |
Number of Stars | 100 Billion |