Novae explode without warning, and even recurrent novae are pretty unpredictable. (For instance, we've been waiting way too long for T Pyxidis to erupt again
But here's a prediction about a recurrent nova that should go off in a specific year: 2009. I've calculated that the recurrent nova U Scorpii, north of Antares and east of the head of Scorpius, should explode any month now. My "crystal ball" is based on old archival photographs and data from amateur astronomers. This brings a golden opportunity for amateurs and professionals to catch the early hours of a nova eruption and to prepare in advance for an intensive observing campaign.
"Recurrent novae" are those that have had more than one eruption observed within a century or so. Classical novae too are believed to repeat, but on timescales of perhaps 1,000 to 100,000 years; we just haven't been watching long enough to see them do it yet.
U Sco is one of the most famous recurrent novae. In quiescence it usually hovers around magnitude 17.6, but in outburst it briefly shoots up by about 8 or 9 magnitudes. In fact, U Sco is the all-time fastest nova known. Its brightening from minimum to maximum takes only about 5 hours, and its decline to two magnitudes below maximum takes about 38 hours. U Sco's last three eruptions, in 1979, 1987, and 1999, were all discovered by amateur astronomers.
TAKE BACK THE NIGHT!
JOIN THE GLOBE AT NIGHT CAMPAIGN, 16-28 MARCH!
At least 2 out of 5 Americans, 1 out of 6 Europeans and 1 out of 10
people worldwide have never seen 90% of the stars in our night sky.
With half the world's population now living in cities, this problem is
only getting worse. Yet you can easily be part of a local solution to
a global problem.
Take back the night! Take a few minutes to monitor your local night
sky brightness, place your measurement on-line noting your location,
date and time and within a few weeks see a map of light pollution
levels worldwide.
Be part of the "GLOBE at Night" citizen-science campaign and make a
world of difference! The GLOBE at Night campaign runs March 16-28,
2009. Help preserve our natural heritage for generations to come. Find
out more information at www.globe.gov/globeatnight . GLOBE at Night is
an official International Year of Astronomy Dark Skies Awareness
cornerstone project.