Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: Roberto on Aug 09, 2019, 22:17:03

Title: LBN 468 in Cepheus - including Gyulbudaghian's Nebula
Post by: Roberto on Aug 09, 2019, 22:17:03
One taken last week during the moonless clear skies' spell.  Turned out better than expected for the amount of time I spent on it (13hrs).  It includes a Hubble type nebula; Gyulbudaghian's Nebula which is fanned by a PV Cephei type star (red in my version).   See a proper shot from the Hubble telescope here:  https://en.wikipedia.org/wiki/PV_Cephei#/media/File:A_changing_fan.jpg

Roberto

(https://cdn.astrobin.com/thumbs/yNXuIV-MaJqD_1824x0_pNrtFuBm.jpg)
Title: Re: LBN 468 in Cepheus - including Gyulbudaghian's Nebula
Post by: Carole on Aug 09, 2019, 23:02:48
VERY nice Roberto

Carole
Title: Re: LBN 468 in Cepheus - including Gyulbudaghian's Nebula
Post by: Roberto on Aug 10, 2019, 06:59:35
Thank you Carole. It's still quite noisy but with the weather we are having now and full Moon approaching, it was time to wrap up.
Roberto
Title: Re: LBN 468 in Cepheus - including Gyulbudaghian's Nebula
Post by: Carole on Aug 10, 2019, 09:00:04
N.B. Your link above leads into a completely different target. 
Also have you tried pronouncing this target  :boom:

This is also actually on my to do list - eventually.

Carole
Title: Re: LBN 468 in Cepheus - including Gyulbudaghian's Nebula
Post by: Roberto on Aug 10, 2019, 10:37:43
The link is to Hubble image of the variable nebula at the very centre of my image. To give some context to the resolution!
Thanks
Roberto
Title: Re: LBN 468 in Cepheus - including Gyulbudaghian's Nebula
Post by: Roberto on Aug 29, 2019, 16:32:14
Just a closing note on this one since the name of the little nebula (marked below) caused so much stir at the meeting last night.

(https://cdn.astrobin.com/thumbs/pqAbL53qqT_4_1824x0_wmhqkGbg.jpg)

https://www.spacetelescope.org/images/potw1316a/

QuoteImages of PV Cep taken in 1952 showed a nebulous streak, similar to a comet's tail. However, these had vanished when new images of the star were obtained some twenty-five years later. Instead, the blue fan-shaped nebula had appeared. Twenty-five years is a very short period on cosmic timescales, so astronomers think that the mysterious streak may have been a temporary phenomenon, such as the remnants of a massive stellar flare — similar to the solar flares we are used to seeing in the Solar System.

At the same time as this was happening, the star itself was brightening. This provided the light to illuminate the newly formed fan-shaped nebula. This brightening might be related to the start of the hydrogen-burning phase of the star, which would mean that it was reaching maturity.

And image of the changing nebula (over several years) - courtesy of Bart Delsaert (https://delsaert.com/)

(http://delsaert.files.wordpress.com/2019/08/gyulbudaghian_animation_2008-2019.gif)

Roberto
Title: Re: LBN 468 in Cepheus - including Gyulbudaghian's Nebula
Post by: Carole on Aug 29, 2019, 17:24:22
How interesting Roberto, thanks for the info.

Carole
Title: Re: LBN 468 in Cepheus - including Gyulbudaghian's Nebula
Post by: MarkS on Aug 30, 2019, 23:06:16
I hope you don't mind but I'm going to give this a go myself - the Iris and LBN 468

I tried it with my Sony A7S a few years ago: http://www.markshelley.co.uk/Astronomy/2016/iris.html
Unfortunately, it was a real pig to process, mainly because of issues with the Sony (background green/purple gradients).  I'm very interested to know how the Nikon Z6 fares.

Mark
Title: Re: LBN 468 in Cepheus - including Gyulbudaghian's Nebula
Post by: ApophisAstros on Aug 31, 2019, 00:14:25
Do the stars change colour because of processing techniques , in the animation ?
Roger
Title: Re: LBN 468 in Cepheus - including Gyulbudaghian's Nebula
Post by: Roberto on Aug 31, 2019, 08:05:17
Mark
That's a great shot and perfectly framed. Please post your results with the new camera if you do this one again.

Roger
No, the change is physical; maybe exaggerated by processing a bit. The star at the point of the nebula is PV Cephei, a young star accreting gas as it forms with high brightness variability. It's precisely what Chris Lintott explained during his talk this week.
See here: http://newburyastro.org.uk/pv-cephei-and-gyulbudaghian's-variable-nebula.html or the links above.

Roberto
Title: Re: LBN 468 in Cepheus - including Gyulbudaghian's Nebula
Post by: RobertM on Sep 05, 2019, 16:27:36
Again a lovely image Roberto.  It's also nice to have a bit of perspective on the objects in the image so thanks for also including that.

Robert