Sirius A


“Sirius A is about twice as massive as the Sun (M) and has an absolute visual magnitude of 1.42. It is 25 times more luminous than the Sun but has a significantly lower luminosity than other bright stars such as Canopus or Rigel. The system is between 200 and 300 million years old.  It was originally composed of two bright bluish stars. The more massive of these, Sirius B, consumed its resources and became a red giant before shedding its outer layers and collapsing into its current state as a white dwarfaround 120 million years ago.”  [ Source: ]

I am by no means an astrophotographer, but I do love the starry sky.  Thus, I just was experimenting a bit last night, focusing on Sirius A, which is very prominent here.

I usually don’t give exposure details, but for my camera, I wanted to find a good ISO and Shutter Speed that captures an image that has reduced digital noise.  I found ISO400 at 5 Seconds, at f5.6, at approx. 50mm, a good combination.

I’m not sure how visually accurate the visual is that I got, of Sirius A, but I am quite happy with the apparent details of the image.

The night sky is visually abstract, so that may be why I sit outside at night and look up at the universe.


    1. Hi Ingo, thanks. Yes, as far as my amateur knowledge of stars and constellations goes, this is Sirius A. It is a binary system with a faint dwarf star, Sirius B. I really enjoy seeing wide-field astro images with twinkling stars, but I wanted to actually try to see and capture the outline shape of the star, and this is what a shorter shutter speed and cropping into the image showed me. It looks like there is a defined edge and sun-like flares around it. As far as my camera technology goes, this is how it has interpreted Sirius A.


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