23 February 2015

Star Party (edit: plenty going on, even if it rains!)

Everyone is invited! Come along to the Star Party, and do some stargazing with the big telescopes, guided by astronomers, who know where everything is, and who can tell you what you're looking at!

You don't have to go to Uplands to come along, or even be a parent...anyone interested in looking up at the sky at night with other people, and expert guidance, is welcome!

There will be a pop-up planetarium (you can book a place at the Wadhurst Star Party webpage) organised by the Dark Skies in the High Weald AONB.

Refreshments will be available (funds to go to Wadhurst Primary School), so just bring your hat, gloves, scarf, blanket...whatever it takes to keep you cosy while you enjoy the night sky!

More information will be available from the High Weald website 

6 February 2015

50 Brightest Stars - how far are they?

Chart showing distance of the 50 brightest stars
I was looking at a table of the 'brightest' stars, and thought it might be easier to visualise how far the stars are away from us if I could see some sort of chart. Not being an expert artist, it isn't brilliant, but the distances are pretty much to scale (Click on it to go to a larger version, then click on it again to zoom in) . 50 stars in one chart might be too many, but I wanted to see them all side by side. This means the chart is pretty large scale to include the furthest of the stars, Deneb (α Cyg) is 2600 light years away!

Funny, I hadn't realised how relatively close most of the brightest stars are (under about 300 ly)...which makes sense, I guess, because you might expect a closer star to be brighter. What is more surprising is how far away some of the brightest stars are.
Three of the stars are more than a thousand light years away - Deneb (2600 ly), Alnilam (1300 ly) and Wezen (1800 ly); then there's another nine stars between 500-1000 ly distant, in order of apparent luminosity: Rigel (860 ly) & Betelgeuse (640 ly) from Orion, Antares (600 ly) & Shaula (700 ly ) from Scorpio, Alnitak (820 ly) also from Orion, Regor (840 ly) from Vela, the sails of Perseus's great southern ship, Mirfak (590 ly) from Perseus, Avior (630 ly) from Carina and lastly Mirzam (500 ly) from Canis Major.
That these stars shine brighter in the sky when they are such large distances just goes to show how they are either stars burning way brighter than our local ones, or they are so much bigger that they are emitting light from a larger surface area. (I shall make a point to find out which Deneb is - a fiercely burning blue-white star, or a huge red giant...Seeing as how white it looks in the sky, I suspect the former)