The Sky This Week , October 21 – 28, 2014 !

The Sky This Week, 2014 October 21 – 28

Here comes the Sun
Sol_141021_1737_02small.jpg
Solar Active Region 2192, 2014 October 21, 17:37 UT
Imaged with the U.S. Naval Observatory’s
15-cm (6-inch) f/9 AstroPhysics refractor,
Thousand Oaks white-light solar filter, and
Canon EOS Rebel T2i DSLR

The Moon emerges into the evening sky late in the week, passing through the setting southern stars of summer as she goes.  New Moon occurs on the 23rd at 5:57 pm Eastern Daylight Time.  Look for Luna about seven degrees north of the ruddy star Antares, which will be low in the southwestern sky an hour after sunset on the evening of the 26th.  Two nights later the Moon’s fattening crescent will be a similar distance northeast or Mars, somewhat better placed among the stars of the “Teapot” asterism of Sagittarius.

We don’t often talk about the Sun in our weekly sky roundup, but this week gives us a couple of reasons to keep a figurative eye on the “Day Star”.  Of course you should never, ever look at the sun without taking the proper precautions, because simply put doing so will cost you your eyesight.  That said, you can safely observe Old Sol by indirect methods, the most tried and true of which is solar projection.  This works very well with binoculars and spotting scopes of modest aperture, and once you’ve tried it you may become a dedicated Sun spotter.  The first thing you’ll need to do is to fix your optics on a tripod.  If you’re using binoculars cover one of the optics with a lens cap.  Now point the optic at the Sun, but don’t look along the tube to sight it.  Instead, look at the ground at the shadow of the optic.  Adjust your pointing until the shadow is smallest.  You will also probably see the projected image of the Sun somewhere on the shadow.  Now hold a sheet of white paper a foot or so behind the eyepiece and adjust the focus until the solar limb and sunspots become clear.  Now call your friends and family out to watch the show.

And what a show it is this week.  On the afternoon of the 23rd the Sun undergoes a partial eclipse by the disc of the Moon.  Here in Washington the eclipse begins at 5:52 pm EDT, and for the next 26 minutes Luna’s “bite” will grow to cover about one-third of the solar disc.  Sunset cuts us off abruptly at 6:19 pm, but for every degree of longitude west of Washington you can add 4 minutes’ duration to the event.  The best views in the U.S. will be from the northern tier of states and Alaska, but everyone in the country will see at least some part of it.

There’s another solar spectacle that’s also occurring this week, and this one could potentially influence some other interesting sky phenomena.  Active Region 2192, the largest sunspot group yet seen during the current solar cycle, is now rotating across the earth-facing side of the Sun.  We’ve seen some impressive spots before in this cycle, but none have been quite this monstrous.  It is nearly as large as the planet Jupiter in size and it’s still growing, making it an easy target for projection with binoculars.  Sunspots are the focal points of powerful magnetic fields that form deep under the Sun’s surface, and as they grow they become charged with magnetic energy.  This energy is released in the form of powerful X-ray bursts that can disrupt communications and pepper geostationary satellites with dangerous electrical currents.  Often huge blobs of matter called Coronal Mass Ejections are liberated with the flares, arriving in Earth’s vicinity a few days later.   CMEs associated with “X-class” flares can cause any number of effects here on Earth; in bad cases power grids can go down due to induced currents in long-distance transmission lines.  In many such instances we’re often treated to displays of the Northern Lights, which can be seen as far south as the Carolinas and Arizona if conditions are favorable.  A good resource for checking on solar activity is SpaceWeather.com, part of the Science@NASA initiative.

Staying in the solar system, we still find ruddy Mars working his way eastward among the stars as he stays ahead of the approaching Sun.  Last week the red planet had a close brush with a comet, and this week the data from the encounter are beginning to trickle in.  Mars is still fairly easy to find in deep twilight in the southwestern sky, but he doesn’t linger for long. He sets at around 9:30 pm.

Jupiter now graces the early morning sky, following the stars of the Great Winter Circle into view.  He is impossible to miss in the eastern sky as the first rays of dawn approach, so if you’re up before the Sun be sure to give him a look.  He’ll continue to work his way into the evening sky where he’ll shed welcome light on wintry landscapes.

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