M27's Goldilocks' Variable Star

[fireballxl5]

After reading a short article in June 2019's issue of S&T by Robert J. Vanderbei on the Goldilocks' Variable Star - see links below, I thought that I'd check my images of M27. Sure enough I had shots from Sept 2012 and Aug 2017 which showed this Mira-type star's variability🙂 Using these images I've created this animated GIF. 
Note that the star was not visible in 2012 and visible in 2017 and although both are HaRGB images, they were captured using very different setups (12" MC and 6" refractor respectively)🙃
 

https://vanderbei.princeton.edu/tex/m27_variable_star/Goldilocks_FocalPoint.pdf

http://www.messier.seds.org/xtra/leos/gl.html

 

PS, the blue cast on the 2012 (not visible) frame isn't so strong at all on the original GIF🤔

Edited December 23, 2019 by fireballxl5
added PS

[wimvb]

Cool! Always nice to see physics in action. Unfortunately that other variable is just outside your fov. 

Edited December 23, 2019 by wimvb

[Mick J]

Fascinating, and well put together, thanks

[fireballxl5]

1 hour ago, wimvb said:

Cool! Always nice to see physics in action. Unfortunately that other variable is just outside your fov. 

The second variable wasn't mentioned in the S&T article and as I'd already aligned & cropped the images to create the GIF and didn't have more time this morning I didn't go back to check this after reading the PDF😊...until now🙂

In fact, the second Mira variable is also in both shots and I've marked them up below.

Thanks for the feedback🙂

CS, Andy

 

 

[JamesF]

I must have some old subs of M27 somewhere.  I shall have to go back through them and compare with my data from this year.

James

[Mr Spock]

It would be interesting to produce a light curve for it. Do we know what its magnitude range is?

[fireballxl5]

1 hour ago, Mr Spock said:

It would be interesting to produce a light curve for it. Do we know what its magnitude range is?

There is some old and limited data from 1997 in the linked article at http://www.messier.seds.org/xtra/leos/gl.html

and slightly more recent 1999 data here: http://tocobs.org/m27.htm

The AAVSO identify the star as V0571 Vul and have an entry here: https://www.aavso.org/vsx/index.php?view=detail.top&oid=63394, detailing a magnitude range of 14.4-17.5 (Rc band) with a period of 214 days.

HTH

CS, Andy

[Mr Spock]

Nice clean curve.