Nova U Σκορπιού

kkokkolis · Φεβρουάριος 1, 2010

Από το Sky & Telescope Alert:

"One year ago, Bradley Schaefer predicted that the recurrent nova U Scorpii was due to explode again. Now it's just happened.

On Thursday morning, January 28th, amateur variable-star observers Barbara Harris and Shawn Dvorak in Florida notified the American Association of Variable Star Observers (AAVSO) that U Sco had leapt to about magnitude 8.0. Less than 24 hours later it was still in its quiescent state at magnitude 188, where it has been since its last eruption in 1999.

Schaefer made has prediction based on a thorough search through old photographic sky-patrol plates since 1900. He found three eruptions that had not been known previously and felt confident that he had a good handle on them all. They come an average of every 10 ± 2 years. So another seemed due.

A lot of astronomers, professional and amateur, have been waiting. Observatory schedules are being preempted, and astronomy satellites are being repointed. Schaefer has been hoping that with his advance warning, this will be the more thoroughly studied nova explosion ever.

Where to look

U Sco is located about 9° north of Antares, currently up in the southeastern sky before the first light of dawn. The farther south you are the better, but even from as far north as latitude 45° U Sco is at least 20° above your horizon before morning twilight begins. To find when that happens at your site, you can put your location into our online almanac. (Make sure the Daylight Saving Time box is unchecked).

U Sco both rises and fades fast. In previous outbursts, it has dropped by 2 magnitude in the first day and a half.

Here are recent AAVSO magnitude estimates.

We expect to have more up shortly"