My God, it’s full of stars
- Dave Bowman, 2001 a Space Odyssey
When you look up from a dark site on a clear moonless night, the sky appears full of stars, almost too many to count.
It turns out that, with the naked eye, one can see anywhere between 5000 to 10000 stars, depending on whom you ask and how they estimate this number and just half of that on a given night because the Earth gets in your way. Still a lot but really nothing when you consider there are billions - maybe hundreds of billions of stars in our Galaxy and trillions of galaxies in the Universe.
It’s a completely different matter when you use optical aid. A pair of 50 mm binoculars can pull in some hundreds of thousands of stars; a small - say 80 mm telescope - like mine-can “ see” millions.
And here is an example. This is the much loved deep southern object known familiarly as 47 Tucanae- Tuc 47 to friends- and it is what is known as a globular cluster.
It contains over a million stars - I am unable to determine what the latest estimate is- a couple of decades ago we used to say it contained half a million stars but that estimate has since been upped.
It’s the second largest of this type of cluster- there are around 150 of these distributed in a halo around our galaxy that we know of.
And quite spectacular in a telescope of any size. It cannot but bring to mind Dave Bowman’s famous exclamation in “2001 a Space Odyssey “
Imaged from my backyard last weekend; an image salvaged despite the usual trials and tribulations that beset the amateur astrophotographer including tangled cables and the camera slamming into the tripod leg and so on and so forth.
Given the long weather forecast it’s going to be slim pickings this summer so you take what you get
What would it be like to live on a planet within a globular cluster? In 1941 Issac Asimov wrote a great short story “ Nightfall “ imagining just that. Highly recommended if you have forgotten it
Sadly the Hubble Space Telescope looked for planets in Tuc 47… and found none. So we have no evidence that planets form within these globular clusters- thus far
https://flic.kr/p/2mGS9cC