June 20, 2019

AstroEvent: A Close Binary Occultation.

Astronomical occultations are always fun to catch. Unlike other astronomical events that often happen over glacial time scales, occultations happen with abrupt swiftness. And besides just being plain cool, occultations can produce real scientific value, data that you can contribute to from your own backyard… and there’s no bigger occulting body in the night sky than our own Moon. This week, I’d like to bring to your attention a fairly bright and interesting star that is currently undergoing a series of lunar occultations this year; Sigma Scorpii. This star shines at magnitude +2.9 in the heart of the constellation Scorpius and is itself a close binary difficult to separate with a telescope. This star is also known as Al Niyat, or Arabic for the “Shield of the Heart,” possibly referring to its visual proximity to brilliant Antares. Sigma Sco is itself a complex system, with a 9th magnitude companion about 20” distant.

[Read more...]

U Scorpii is Currently in Outburst.

This is a quick shout out for all variable star watchers to catch a rare object; recurrent nova U Scorpii is currently in outburst. Followers of this space will recall that we blogged about this flare star last September; the AASVO issued Alert Notice 415 earlier today stating that U Sco is currently at +8 magnitude and climbing. Scorpius is currently placed low in the south east in the hours before dawn, and U Sco should be a binocular object. This is a fast one, so be sure to try and catch it over this next few mornings, as after this weekend it will have propably faded out, and we will also have a past Full Moon to contend with… good luck!

14.9.9:U Scorpii:A Nova in Waiting?

(Image credit & copyright courtesy of Mark A. Garlick; used by permission.

Please do not use this image in any way whatsoever without first contacting the artist).

Recurrent novae are among the rarest of beasts. While one-off galactic nova come and go throughout the year, recurrent novae are among those very few stars that have been known to exhibit nova-like flares multiple times. This week, I turn your attention towards U Scorpii, a known recurrent nova in the head of the constellation Scorpius. As the bright Moon is currently out of the evening sky, now and next month is the time to peek at this unique star before it slides behind the Sun. First discovered in 1863 by English astronomer N.R. Pogson during an outburst, U Scorpii stands as one of the fastest recurrent nova known, [Read more...]

Astro-Event of the Week; 02.06.09: An Antares Occultation.

An occultation of a bright star is well placed for observers in the Americas this weekend. The waning gibbous Moon will occult (i.e. pass in front of) the bright star Antares, also known as Alpha Scorpii. The action begins around 10:00 PM EDT and the Moon will cover up Antares for up to an hour and a half, depending on your latitude. Although the Moon will only be 16 hours away from Full, Antares at about magnitude +1 will be an easy naked eye target, and the skies will be completely dark along East Coast longitudes.

[Read more...]