Wednesday, January 02, 2013

The Moon Occults Spica, Sunday January 6, 2013

Morning sky as seen from Adelaide at 5:00 am ACDST on January 6 showing the Moon about to occult Spica (click on image to embiggen).

The Moon occults the bright star Spica (alpha Virginis) on the morning of Sunday the 6th. The occultation will be in daylight from most parts of Australia.

While the Sun has risen, careful positioning of telescopes or binoculars means that you can obverse the occultation. Spica is bright enough to see in the early morning with optical aide, although invisible to the unaided eye.

Make sure your binoculars and telescope are behind a wall or some other solid object (not trees) so that you cannot accidently get the sun in your telesope of binoculars. NEVER LOOK DIRECTLY AT THE SUN WITH BINOCULARS OR TELESCOPES AS SEVERE EYE DAMAGE WILL RESULT.

Simulated telescopic view of Spica about to go behind the Moon at 5:26 am, as seen from Adelaide. 

The bright limb of the Moon covers Spica at 5:26 am ACST Adelaide, 5:20 AEST Brisbane (daylight graze), 6:17 am AEDST Canberra (daylight), 5:50 am AEDST Hobart (daylight), 6:11 am AEDST Melbourne (daylight), 2:26 am AWST Perth and 6:24 am AEDST Sydney (daylight).

For all states except WA, the Moon oves of Spica after sunrise. The dark limb of the Moon uncovers Spica at 6:35 am ACDST Adelaide (daylight), 7:22 am AEDST Canberra (daylight), 7:05 am AEDST Hobart (daylight), 7:22 am AEDST Melbourne (daylight), 3;34 AWST Perth and 7:19 am AEDST Sydney (daylight).

With the Moon one day past first Quarter, this event is really best seen with binoculars or a small telescope (especially for the reappareance of the star during daylight). If you have a tripod or other stand for your binoculars, it will be much easier to observe.

Again, I emphasise that if you are observing after Sunrise, please ensure that there is no way for you to accidentally glimpse the Sun. Make sure the Sun is well behind a wall or other substantial object.