Our active Sun in February 2025

Königsberg Observatory (left) where Friedrich Wilhelm Bessel made the first successful distance measurement to a star other than the Sun...

A short explanation An image from a video visualisation of the expanding and accelerating universe ( Credit : NASA's Goddard Space Flight...

See below for my astronomy videos that I have created over the last 2-3 years. Episode 1 - Comets Episode 2 - Black Holes Episode 3 -...

By Jeff Portelli Les Dalrymple was passionate about astronomy, and an exceptionally knowledgeable and experienced amateur astronomer. He...

Sydney City Skywatchers member Garry Dalrymple has been observing sunspot activity lately with a small aperture telescope fitted with a...

An easy-to-use walk around guide. By Garry P. Dalrymple The visibility of the stars and the planets is a restriction placed on all of us...

Dr Toner Stevenson, History Affiliate, School of Humanities, The University of Sydney This blog post is to recognise Margaret Colville...

The dictionary defines binary as “composed of or involving two things”, so a binary star is a system composed of two stars which orbit ...

11th November 1572 Supernova SN1572, also called B Cassiopeiae, is first observed by Danish astronomer, Tycho Brahe. The “new star” was...