A new 6th magnitude nova that was discovered in Sagittarius on March 15th by John Seach of New South Wales, Australia brightened quickly to magnitude +4.3 on March 22nd. On this day it could be easily seen with the naked eye and was bright in binoculars. Although now fading, the nova should remain within amateur range for days if not weeks to come. On March 24th, it stood at magnitude +5.5.
Novae are out-bursting stars. They occur when a compact white dwarf star accretes so much material from a close companion that it undergoes a thermonuclear explosion on its surface. This leads to a brief dramatic sudden increase in brightness. They are different to supernovae, where a catastrophic destructive event is caused by the collapse of the core of the star.
The finder chart below shows the position of the nova. It's located in the northern part of the middle section of the famous Sagittarius "teapot" asterism. It has been designated as Nova Sagittarii 2015 No. 2.
The nova is best seen from Southern and tropical latitudes during the early hours of the morning where it appears high in the sky. From northern temperate latitudes it's best to look just before sunrise, where it appears low down towards the southeast. Although fading, novae are unpredictable objects and they can burst into life again at anytime....so keep watching!
You can submit your magnitude estimates of the nova to both the British Astronomical Association's Variable Star Section or the American Association of Variable Stars.
The nova coordinates are:- R.A. = 18h 36m 56.8s, Declination = -28d 55m 40s (J2000).
***UPDATE - March 31***
Nova Sagittarii 2015 No. 2 -- recent outburst now back at magnitude +5.0. Naked eye, easy with binoculars.
***UPDATE - April 20***
Nova Sagittarii 2015 No. 2 -- faded slightly to magnitude +5.5. Faint naked eye, easy with binoculars.
***UPDATE - June 20***
Nova Sagittarii 2015 No. 2 -- now faded to magnitude +10.0. Medium size telescope recommended.