- This topic has 12 replies, 4 voices, and was last updated 2 weeks, 3 days ago by
.
-
Posts
-
There is a suggestion in this stacked image of 40 x 60 sec exposures recorded on 15th December with a 0.35 m SCT and Rc filter, that Gyulbudaghian’s Nebula might be starting to reappear.
David
Attachments:
Hi David,
I think that V shape and the right hand wing (on your image) feature have been faintly visible on some unfiltered images since the summer.
Such as here:
https://britastro.org/observations/observation.php?id=20221129_230438_ac6a218c4ac94ed0
and
https://britastro.org/observations/observation.php?id=20221129_230930_656c96e63f3df518Was it absent in your similarly exposed Rc filtered images from earlier in the year? The nebula is heavily reddened, so you might well see changes before those of us working unfiltered noticed them.
Do you still measure the nebulosity brightness at all? What does that curve say?
Would be nice for this or McNeil’s to reappear at last. Looked at Thomme’s last night and can’t see much change since I started looking at it and McNeil’s is absent with V1647 Orionis in the 19.5-20.5 mag range when skies are clear enough to detect it.
Happy Solstice!
Grant
Hi David,
I attach my image of Mr G taken last night but it’s only a 20 minute total exposure so doesn’t show things as clearly as yours. The fan shape is there plus a hint of the extension. I agree with Grant that the fan shape has been there a while. Indeed Mike H commented on it when he posted his image on 23rd November. However I need to check more of my images but I don’t think the fan shape was there before 9th November. So maybe the nebula is trying to return! I’m sure we will keep checking!Richard
Attachments:
Hi Grant,
My attempts to image the nebula earlier in the autumn have been affected by either thin cloud, haze or moonlight making the nebula barely detectable. This was a really clear night here and the extended E wing of the nebula was more prominent than I had seen it for most of 2022. Trying to measure the flux from the nebula is still problematical. I can only detect a very slight increase in both PV Cep and the nebula.
David
Thanks for the headsup. Your observation really does suggest we all need to keep a close eye on it in the months ahead.
This image taken on 14th August 2023 shows the nebula has brightened considerably since I last imaged it on 12th July. It is a stack of 29 x 60 sec images with an Rc filter on an 0.35m SCT under good conditions. The bright stars in this stacked image are saturated. I measured the mean Rc magnitude of PV Cep from the individual images as 16.93 +/- 0.05.
David
Attachments:
Interesting to see that PV Cep really is recovering after a brief drop in brightness to nearly 18th mag in June.
It would be nice to see another outburst in the nebula. Certainly looking hopeful.
Now if McNeil’s would come back again too, that would set us up for a very nice winter.
This image of Gyulbudaghian’s Nebula recorded on 19th December 2023 is 23 mins of integration with a 0.35m SCT at F/5 and Rc filter. It shows the core of the nebula is slightly brighter than it was in my post a few months ago.
David
Attachments:
David,
By chance I captured an unfiltered image of Gyulbudaghian’s nebula at roughly the same time as you.
Mine is with an f/4 0.3m Newt, unfiltered and the product of 90x 30sec x2 exposures.
My unfiltered measurement of PV Cep sees it at 16.35, slightly down from a few weeks ago.
Have you considered redoing the analysis you did for your paper a few years back? The much longer duration dataset would make it interesting.
Attachments:
I recorded and stacked 34 min of Rc images of PV Cep last night, 22nd October. These show that PV Cep was slightly fainter than the previous month at Rc = 17.24 and that the northern part of Gyulbudagian’s Nebula remains faint while the southern part is brighter than I remember seeing it for a long time. The southern part of the surrounding molecular cloud may be becoming more transparent as it seems less likely that changing illumination from PV Cep is the cause.
David
Attachments:
By coincidence David I also imaged PV Cep and the nebula last night. 50 x 1 minute exposures, I’ve just posted the result in the gallery. I agree with your comments on the current visibility of the nebula.
Richard
An A&A preprint on ArXiv today might me be interest: Two epoch spectra-imagery of PV Cep outflow system.
The authors describe features in the associated HH object and their kinematics.
They report a newly-formed HH knot, which they presume formed during the large maximum of PV Cep star in 1976-1977.
- You must be logged in to reply to this topic.