Description | Images |
Object name: NGC1857Designation(s): NGC1857, NGC 1857 is a small open cluster in Auriga about 18,700 light-years distant according to WEBDA. It is an original Herschel 400 object which put it on my to-do list when nothing better was in position. In this case, weather was poor and star clusters cut through haze. My notes from 1985 indicate it reminded me of NGC 2362 around Tau Canis Majoris. However, unlike Tau the bright orange star I was referring to is not likely a member of the cluster. Hipparcos puts the star at only 1500 light-years, far closer than the cluster. The cluster's age is listed by WEBDA at 133 million years, certainly old enough to harbor a massive red giant. That star is SAO 57903, a K5 or K7 star depending on which reference I look at. The cluster is reddened by about 0.49 magnitude according to WEBDA. I don't know if the other orange stars are cluster members or not. |