Gum 50 & Trumpler 23

While working through South African astronomer, Magda Streicher’s, list of delightful asterisms to enjoy the pretty in the night sky, I have come across some very interesting deep-sky objects in the nearby regions of the sky.

I noticed a pinkish-reddish object to the north of asterism, Streicher 34. I ran the co-ordinates in Aladin Sky Atlas and identified this as Gum 50. Then another surprise! I also found the faint but destinctive open cluster, Trumpler 23 northeast of Gum 50. The cluster has an interesting shape and almost looks connected to Gum 50 by a string of stars. Could they be somehow connected?
If only I could understand what’s been written in scientific papers by Y M and Y P Georgelin and Veta Avedisova, I would have a clearer idea.

At one stage Avedisova placed Gum 50 and Trumpler 23 in the same star forming region. After measuring distances and determining spectral classes of the stars, the Georgelins cast doubt on whether the cluster was associated with Gum 50, which goes by RCW 99 as well.


Nightfall contributing writer Carol Botha has been opening new vistas for her ASSA colleagues. Foresaking the joys of South Africa’s ever present tremulousness thanks to Jet Stream, our subtropical humidity, the frigid winds and practically inescapable light pollution, Carol now sits in her comfy office surrounded by panoramic computer monitors, and a web link to the Slooh network of robotic telescopes located in Chile and the Canary Islands

In the process she captures spectacular star fields that hide objects very few observers have ever seen or photographed. One of them is this faint but distinct snap of the old Galactic thick-disc Globular Cluster Lynga 7

This Cluster’s location and colour spectrum suggests that it originated in a dwarf galaxy that the Milky Way shredded multiple billions of years ago. Spot it? (it lies at x_-5.y=0 on the grid) At 26,000 light years from the Sun, it is a faint fuzzy indeed

Written en published by Nightfall Editor, Douglas Bullis –