IC 1613 [SEP] constellation
IC 1613
IC 1613 (also known as Caldwell 51) is an irregular dwarf galaxy, visible in the constellation Cetus near the star 26 Ceti. It was discovered in 1906 by Max Wolf, and is approaching Earth at 234 km/s.
IC 1613 is a member of the Local Group. It has played an important role in the calibration of the Cepheid variable period luminosity relation for estimating distances. Other than the Magellanic Clouds, it is the only Local Group dwarf irregular galaxy where RR Lyrae-type
and its illuminating star are a very early stage planetary system.
- IC 447, a reflection nebula.
History.
In Western astronomy, Monoceros is a relatively modern constellation, not one of Ptolemy's 48 in the "Almagest". Its first certain appearance was on a globe created by the Dutch cartographer Petrus Plancius in 1612 or 1613 and it was later charted by German astronomer Jakob Bartsch as Unicornu on his star chart of 1624.
German astronomers Heinrich Wilhelm Olbers and Ludwig Ideler
indicate (according to