Watch the Moon Occult Aldebaran for Europe Wednesday Night

The Moon occults Aldebaran on October 30th, 2015. Image credit and copyright: Zalatko Orbanic

An early Christmas present is on tap this week for observers in Europe, the United Kingdom and northern Asia, as the waxing gibbous Moon occults (passes in front of) the bright star Aldebaran on the evening of Wednesday December 23rd.

The event will see the 87% illuminated Moon occulting the +0.8 magnitude star Aldebaran under dark skies on Wednesday evening December 23rd across Europe, the United Kingdom, northern Africa and northern Asia. Initial ingress will occur across the slender dark limb of the waxing gibbous Moon, with egress against the bright illuminated limb. Usually, the brilliant Moon would wash out any star near Full, but Aldebaran should remain visible, even during egress.

The International Occultation Timing Association (IOTA) maintains a page listing local circumstances for towns and cities in the occultation path. This is the 13th and final occultation of Aldebaran for 2015 (one for each lunation), and the 13th in a series of 51 stretching from January 29th, 2015 to September 8th, 2018.

Clouded out? The Virtual Telescope Project is planning on broadcasting the occultation hosted by astronomer Gialuca Masi live starting at 17:45 UT.

Why observe occultations? From transits to eclipses to events such as this week’s involving the Moon, the chance alignment of celestial bodies often gives us a chance to discover something of their true nature. Close binary stars have been uncovered during occultations. Transits reveal exoplanets to platforms such as Kepler. Some stars exhibit a tiny angular diameter, apparent only during occultations. The passage of an asteroid in front of a star can reveal something of its shape and size. And in the case of bright star grazes along the lunar limb, such as passage can be used to map the Moon’s jagged edge in profile.

The southern limit graze line for Wednesday’s —> Read More