The cool thing about astronomy is that I often browse the night sky and come across clusters or other objects I haven’t seen before. This happened a few weeks ago, when I was browsing the bit of sky between Alpha Centauri and the beautiful star cluster, NGC6067. While looking around and examining the stunning Milky Way star field, I came across some stars I could not remember seeing before. It was a lovely group of bright stars, maybe about ten in a slightly elongated distribution. I checked out Sky Safari and saw that the cluster is called NGC6025.
The location is just off Beta Trianguli Australis, in the constellation of Triangulum Australe. If you follow a line from Beta to Alpha Centauri until it’s next to Beta Taianguli Australis, then you’ll be in roughly the right place.
Whenever I see a cluster of stars I have not seen before, I want to find out more. So I dusted off the old textbook from my astrophysics study a few years ago and analysed the cluster to understand more about it. A good place to start is to see what other people have found out about this cluster. There are a few articles from the 1950s and 1970s, and a few more recent papers, so there is not much out there.
Alejandro Feinstein (1971) calculated the distance to be 760 +/- 70 parsecs, which broadly agrees with A R Hogg from his 1953 work, where he calculated 805 parsecs. Feinstein also estimated it to be 100 million years old. This work is a great place to start working out more about this very nice cluster.
Using Gaia DR3 data (credit here and an acknowledgement below), we can do more analysis and learn a little about this cluster. The picture on the right is the Colour Magnitude Diagram made by the author, derived from photometry conducted by ESA’s Gaia spacecraft and released under DR3. The mean distance, 779 parsecs, was calculated from the parallaxes of the individual stars, which agrees reasonably well with previous estimates. Additionally, the age was estimated by fitting a MIST-generated isochrone for a 100-million-year-old synthetic cluster with -0.48 FeH metallicity.
Above is a 3D representation of the cluster. You can use the mouse to look around and double-click on a star to get its designation and estimated distance. This is to give the reader an idea of the cluster’s distribution.
This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement.
