2017 August 27

Asteroid (6925) Susumu to occult a mag 5 star, Sept 9/10

Alex Pratt

At 23:44 UT on the night of September 9 ( 00:44 BST on September 10) the mag 17.8 asteroid (6925) Susumu is predicted to occult the mag 5.1 star sigma1 Tauri (HIP 21673, UCAC4 529-009019).

Details and finder charts are available here:

(6925) Susumu / HIP 21673 event on 2017 Sep 09, 23:51 UT

The target star, which is located near Aldebaran, could be occulted for up to 1.8s causing a temporary drop in brightness of 12.7 magnitudes. This short duration is ideally suited for video or drift scan recording. It should also be an attractive event for visual observers using minimal optical aid.

The predicted ground track, only 26 km wide, passes over or near Snowdonia, Chester, Liverpool, Sheffield, Leeds, York and Hull, although it’s worthwhile observing from a location 100km either side of this region. A more detailed ground track accompanies this article, courtesy of Occult Watcher.

It’s suggested that attendees at the BAA Chester Weekend could monitor the event in groups of widely-spaced observers, several km apart. Note that the star’s altitude will only be about 14 degrees.

Chester AS Chairman, Andrew Bate, has kindly made one of his fields available to anyone who might want to try and observe this event (no guarantees of success are given!). The field is near the village of Waverton, which places it at the extreme edge, or even just outside, the most likely track which is currently predicted. This is a rural area some 3.5 miles south of Chester city centre. Observers will need to provide their own transport and instrumentation (e.g. binoculars, small telescope, imaging equipment)

Please send reports of any observations, whether negative or positive, to the Assistant Director (Occultations) of the Asteroid and Remote Planets Section, Tim Haymes at tvh.observatory AT btinternet.com

There is an observers’ Quick Guide and Detailed How To on Tim’s website.