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Excellent photometry and analysis as ever
Many thanks Tony,
The best paper I can find is this one from 1993 and there does not seem to be a modern analysis as far as I can see.
Photometry of EF Pegasi during Superoutburst
The authors say the following in the abstract:
EF Pegasi was observed photometrically during a superoutburst in 1991 October. Superhumps seen during these observations were best fit with a period of 2h .09. This period is used to determine a likely orbital period of 2h .05 and a mass ratio (M_2/M_1) of 0.26. Distance estimates for EF Peg give values of 250 to 600 pc.
Cheers
Ian.<p class=”wp-dark-mode-bg-image”>Isn’t this object likely to show superhumps during a superoutburst ? VSX lists an orbital period of 2.01 hours
Hi Tony,
Thanks. Just to prove your point here’s a long run of nearly 7 hours on EF Peg from last night in Spain. (2025-08-30 19:46 to 2025-08-31 02:28 UTC). The superhumps are very clear and you can see the Lomb-Scargle period analysis gave 2.0988 hours!
Cheers
Ian.Attachments:
Yep, it’s very tricky to measure. It’s easier visually. Unscrew your camera…;-)
How about this, Gary…this from last night – just over an hour.
Cheers
Ian.I also did a Generalised Lomb-Scargle period analysis in Peranso (Using my long run on 22nd). It seems there is a periodic strong component of about 0.07 days.
See attached.Cheers
Ian.Attachments:
I’ve been looking at your t/s this afternoon, and it does indeed look interesting. Good stuff!
Thanks Gary,
Got it again last night – see attached. I think the peak might have been the previous night as it’s fainter by about a tenth of a mag.
Will keep at it…
Ian.
Hi all,
HT Cas now fading down to 16th/17th mag in V after being at 12-ish. Also, the big pre-eclipse humps seem to have gone, or reduced.
See last night’s run attached.
Ian.
That’s exactly what it is Ian – orbital hump just prior to eclipse. I’ve seen these before visually, and it can take you by surprise!
Thanks Gary,
Here are two more eclipses from last night. Getting slowly fainter overall.
Ian.
Very nice photometry, Ian.
Looks like a pre-eclipse hump (due to accretion hot spot).Thanks Jeremy,
I’ll keep monitoring it and get longer and longer runs on it as we get our nights back!
Ian.
Hi all,
A better image from me. This time 36 x 90s with L filter.
https://britastro.org/observations/observation.php?id=20250728_122425_2b3fb6faab2f3379
I measured the V mag to be 17.5 +/-0.1 using an aperture radius of 12 pixels (0.48 “/pix) with APASS V mag band.
Ian
Nice one Cyril
…nice one son…let’s have another one!
😉I finally managed to get it!
https://britastro.org/observations/observation.php?id=89413
Cheers
Ian.Hi Grant,
Yes, I wrote an ASCOM Alpaca driver for my dome 2 or 3 years ago. I believe it was the first ever Alpaca dome driver. Works like a charm.
However, it was written in Python. It runs on a Raspberry Pi.
Ian.
Sad news!
I’ve known Storm since I was a young teenager in the SDAS (South Downs Astro Soc.) in the early 70’s.
Ian.
Hi all,
It seems SU UMa has brightened again. Last night was around 12.75 in V. See attached.
Cheers
Ian.Yes, this is typical and a diagonal is normally required. All my modern refractors are the same. It allows for lots of backfocus for Cameras, filter wheels and OAGs.
Ian.
Thanks Gary,
I’ve uploaded my R, V and B results from last night – it seems to have steadied. I’ll continue to observe it when I can and my data is always in the BAA database if it’s needed.
Cheers
Ian.Attachments:
Hi all,
There’s a small brightening of OJ 287 going on. Not sure if it will be significant.
Cheers
Ian.Attachments:
