Terry's Astronomy Thread.

[Bluearrowll]

What's in the sky tonight?
October 31, 2013

-Halloween is moonless this year. Spot Venus in the southwest as twilight fades, and Vega very high in the west after dark. Higher above Vega is Deneb. A greater distance to Vega's left, look for Altair.

-Algol, the Demon Star, is at minimum light in eclipse for a couple hours centered on 10:35 p.m. EDT.

-High-latitude sky watchers should be alert for auroras on Halloween. A CME is expected to hit Earth's magnetic field on Oct. 31st, possibly sparking polar geomagnetic storms. In northern Norway, the show got started early with this display on Oct. 30th. "We witnessed a very powerful outburst of auroras with bright colours," says photographer Bjørn Jørgensen of Tromsø. And that was before the CME arrived...

-As Oct. 31st begins, indicators still suggest a CME is approaching Earth. NOAA forecasters expect a G1-class geomagnetic storm when it arrives. Watch for the shock here.

Astro Picture of the Day:
October 31, 2013

Source:
The dark Horsehead Nebula and the glowing Orion Nebula are contrasting cosmic vistas. Adrift 1,500 light-years away in one of the night sky's most recognizable constellations, they appear in opposite corners of the above stunning mosaic. The familiar Horsehead nebula appears as a dark cloud, a small silhouette notched against the long red glow at the lower left. Alnitak is the easternmost star in Orion's belt and is seen as the brightest star to the left of the Horsehead. Below Alnitak is the Flame Nebula, with clouds of bright emission and dramatic dark dust lanes. The magnificent emission region, the Orion Nebula (aka M42), lies at the upper right. Immediately to its left is a prominent reflection nebula sometimes called the Running Man. Pervasive tendrils of glowing hydrogen gas are easily traced throughout the region.