NGC 2551
NGC 2551 is a lenticular galaxy in the constellation Camelopardalis. The galaxy lies about 120 million light years away from Earth, which means, given its apparent dimensions, that NGC 2551 is approximately 60,000 light years across. It was discovered by Wilhelm Tempel on August 9, 1882.
Characteristics
NGC 2551 is categorised as a lenticular galaxy however the galaxy features spiral arms. The galaxy has two well defined narrow spiral arms and many arm fragments, with the spiral pattern being between a grand design galaxy and a multiple spiral arm pattern. The galaxy is seen at an inclination of 50°.The galaxy has a disk of counter-rotating gas forming stars. It is possible the gas of the disk was accreted from a gas-rich satellite. The star formation rate of galaxy based on the H-alpha is estimated to be 0.65 per year.
In ultraviolet a ring is visible lying 15 to 30 arcseconds from the nucleus. Apart from excitation from star formation there is also excitation from post-AGB stars and shocks in the northern inner part of the ring. The galaxy also has a hydrogen disk which appears disturbed, probably due to interactions with other galaxies.