The waxing gibbous Moon moves through the Hyades followed by an occultation of bright star Aldebaran

On the evening of January 19th / 20th observers in the USA, Canada, Western Europe and South Greenland will be able to watch the 10-day-old waxing gibbous Moon occult first-magnitude orange giant star Aldebaran in Taurus. Before that the Moon will pass in front of one of the best naked eye and binocular open clusters in the sky, the Hyades.

The first bright lunar occultation of 2016 starts around 19:00 UT (19:00 GMT - 14:00 EST) on January 19th with the Moon positioned at the edge of the very large and loose Hyades open cluster. Spanning 5.5 degrees of sky the Hyades apparent diameter is equivalent to 11 times that of the full Moon. It's also the nearest open cluster to us.

Over the following few hours the Moon will then pass in front of a number of stars in the cluster. The event can be followed with the naked eye and even better with a pair of binoculars or a small telescope. In Europe the sky will already be dark but from the United States and Canada it will still be daytime. By the time of sunset from eastern US and Canadian locations the occultation of the Hyades will be already underway.

The highlight of the evening occurs when the Moon occults Aldebaran (α Tau - mag. +0.9) with the exact timing depending on the observer's location. For example, from London, England the star disappears behind the advancing lunar limb at 03:24 GMT (Jan 20). The Moon then re-appears about 20 minutes later. From New York City, the occultation begins at 21:31 EST ending at 22:43 EST (Jan 19). From Los Angeles, the occultation begins around sunset at 17:03 PST and finishes at 18:14 PST (Jan 19).

See also

The Planets this Month - January 2016