Printer Friendly

Always expect the unexpected!

On the evening of 2012 October 23 I received TA E-circular 2864 which said:

VARIABLE STAR AMONG THE HYADES STARS: Ian Shelton, Mount Allison University, University of Toronto relays on The Astronomer's Telegram 4513 that a possibly new very red star of magnitude 6 has been recorded ... the coordinates are: RA 04h 23m 29s DEC +17 58' 29" (+/-10"). This position is 2.23 arcmin south of the star GSC 1268-1045 ...




As the discoverer was the man who discovered Supernova 1987a in the LMC, I believed the report to be credible and imaged the field that evening at the reported position, subsequently finding no new object when compared to a POSS1-DSS [Palomar Observatory Sky Survey-Digitized Sky Survey] downloaded image. In fact Ian Shelton had immediately withdrawn his discovery claim in ATEL 4514 after he found that his suspect star was in fact an optical reflection in his camera system from the bright star Aldebaran located only 3[degrees] away.

However, during detailed examination of the image taken to investigate the claim I noticed that there was some difference between my image and the POSS1 image. This difference took the form of a star that seemed to have changed its position quite markedly. I suspected that I had stumbled on a large proper motion star, and that the 57 years between the two images showed its movement. The star in question did indeed turn out to be a known proper motion star, and was identified by Nick James for me using my Astrometrica measured positions and the VIZIER search facility.

I attach three annotated images, POSS1, POSSII and my own image for comparison.

Measurement in Astrometrica of the positions of the star in the three images gave the following values:

POSS1: RA 04 23 25.39, Dec +17 53 51.5

POSSII: RA 04 23 25.71, Dec +17 53 48.9

OWN: RA 04 23 25.95, Dec +17 53 43.49

The magnitude of the star on my image was measured at 15.8 RC.

It is always worthwhile examining in detail any CCD frame taken for any purpose, as you never know what other objects of interest may be recorded at the same time. I do not claim any significance in this 'find'--I only want to point this out as an example of the occasional serendipitous nature of discovery in astronomy.

Denis Buczynski

Tarbatness Observatory (IAU Code i8l), Highland Scotland
COPYRIGHT 2012 The British Astronomical Association
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2012 Gale, Cengage Learning. All rights reserved.

Article Details
Printer friendly Cite/link Email Feedback
Title Annotation:Observers' Forum
Author:Buczynski, Denis
Publication:Journal of the British Astronomical Association
Date:Dec 1, 2012
Previous Article:NGC 457--an Owl in Cassiopeia.
Next Article:Conjunction of Uranus with 44 Piscium, 2012 September 22/23.

Terms of use | Privacy policy | Copyright © 2018 Farlex, Inc. | Feedback | For webmasters