HD 38451: The Star that Changed Colour

In 1850, astronomer John Russell Hind was keeping a close eye on the star HD 38451. He originally observed it two years earlier, noting its strong red appearance. Hind was interested in variable stars and had noticed that many red stars showed interesting variations, so he suspected that HD 38451 might be variable too. What he saw, though, took him completely by surprise: HD 38451 had completely changed colour and now appeared as a brilliant blue-white, which it remains to this day. At the time this change lacked any explanation, and even to this day there are unanswered questions about the behaviour of this star. Join me as I tell the story of what we now think happened in 1850, what modern observations tell us, and what we still don't understand about HD 38451.

Our speaker Adam McMaster is an astronomer and postdoctoral researcher at the University of Southampton (and recently-completed PhD student at the Open University). His work specialises in the use of citizen science to find rare and interesting things in large astronomical surveys. Currently he is searching for the gravitational microlensing signatures of black holes in data from the TESS satellite.

Host or Publisher Mexborough & Swinton Astronomical Society