2019 April 7

Observer’s Challenge – Occultation of M44 the Beehive Cluster by the Moon

Dr Paul G. Abel

Date: 2019 April 13th
Start Time: 2000 UT (2100 BST) to 2300 UT (Midnight BST)

On 2019 April 13th, a 62% illuminated waxing gibbous Moon will pass south of the Beehive Cluster (also known as M44) in the constellation of Cancer. From around 2000 UT (as the sky is starting to get darker) to 2300 UT, the Moon will pass in front (i.e. occult) a number of stars in the cluster (see Figure 1)

For those people who attended the Winchester Weekend on 5th-7th April, you will remember that this was one of ‘Pete and Paul’s Observing challenges’. Even if you weren’t at Winchester, this is a lovely event to watch and requires only a pair of binoculars or a small telescope to view.

There are three stars that are in easy range of binoculars or a small telescope to watch out for and these are:

• HIP 42327, a mag +6.7 star which will reappear from the bright limb at about 2025UT
• HIP 42542, a mag +6.8 star which is occulted at 2040UT and re-appears at 2126UT
• TYC-1395-2321-1, a mag +7.8 star which is occulted at 2045UT and re-appears at 2148UT

Figure 2 shows the location of these stars in the Beehive Cluster. The times given here will vary a little depending upon your location in the country. There are a number of free planetarium software now available which you can use to find out the timings of the occultations from your location.

Paul G. Abel

Please do post any observations of this to your BAA Member Page

[Thumbnail image taken from Stellarium]