The sky around Collinder 140 at true scale, north up and east left, with stars to magnitude 8. The circles show the field of a low-power eyepiece and of 10×50 binoculars.
Collinder 140 is an open cluster in Canis Major, 1,230 light-years away
Collinder 140 is an open cluster in the constellation Canis Major, 1,230 light-years away. It shines at magnitude 3.5 and spans 42′ of sky, about 15 light-years across. It is visible to the naked eye from a dark site, and it is highest in the evening sky in February.
Open cluster: a loose group of a few dozen to a few thousand young stars born together from one cloud of gas. They drift apart over a few hundred million years and lie in the disk of the Milky Way.
Finding Collinder 140 from Aludra
Collinder 140 lies 2.7° south of Aludra, the magnitude 2.5 star. Three fingers held at arm's length cover about 5°.
Collinder 140 is highest in the evening in February
The chart gives its height above the horizon at 9 pm through the year, from 60°N to 40°S. It can be seen from the whole southern hemisphere and north to about 58°N, and never sets south of 58°S.
Collinder 140 is 1,230 light-years away
The light seen from Collinder 140 tonight left it about 1,230 years ago, around 796 AD. It ranks 7 of 78 by distance among the star clusters on Go Astronomy. Distance source: Gaia DR3, Hunt and Reffert 2023.
Objects within 6° of Collinder 140
No other Messier, Caldwell or Herschel 400 object lies within 6°.
