Earlier today Japanese amateur astronomer Koichi Itagaki photographed a new bright nova in the constellation Delphinus (del-FYE-nuss). At the time it was a little below the naked eye limit (6.8 magnitude) but it’s since risen to around 6. That means observers with dark skies can see our new guest without optical aid. And if you don’t have dark skies, don’t worry. You’ll spot the star in any pair of binoculars.
For the moment, the new object goes by the cumbersome temporary designation PNVJ20233073+2046041 (PNV stands for possible nova). Once fully confirmed, it will receive the friendlier Nova Delphini 2013 moniker.
What’s exciting about this “new star” is that it’s just gearing up and could brighten even more. I recall another nova in Delphinus – Nova Delphini 1967 – when I was a wee teenager. That one shot up to magnitude 3.5 and was easily visible in the suburbs with the naked eye.
Using the chart above, I hope you’ll be able to find the nova the next clear night. It’s located about 5 degrees (3 fingers held together at arm’s length against the sky) above the little diamond that forms the top of Delphinus the Dolphin. The numbers on the chart are star brightnesses or magnitudes with the decimal omitted (80 = 8.0 magnitude). The brighter the star the smaller the number. You can use the labeled stars to follow changes in the nova’s brightness over the coming nights.
Novas are not actually new stars despite their name. They occur in binary or double stars containing a superdense white dwarf star orbiting with a normal sun-like star. The dwarf steals matter from its companion, heats and compresses it to high temperature and a thermonuclear explosion occurs. Unlike supernovae, a nova eruption typically doesn’t tear the star apart.
To read more about the new object and find additional maps, please check my post on Universe Today.