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Interesting ATel update on spectroscopy by Teyssier et al, including Robin Leadbeater and Hugh Allen
https://www.astronomerstelegram.org/?read=18053Three of the authors have another paper on superoutbursts of YZ Cnc based on TESS photometry and long-baseline ground-based observations.
The ApJ accepted manuscript is available here.
Multiple Seestar T CrB light curve beginning July 4th 2024. This curve is derived from 397,667 (ish) exposures up to September 9th 2026. There are 264 data points here each derived from a stack of as much of the night as I can manage. Processed with Pixinsight and differential photometry with AstroImageJ. Exposures are 2-30 sec. Now investigating how my green channel magnitude matches V magnitude.
Good to see you persevering with this, Steve. Keep going!
I changed the title of this thread not Jodrell Bank NOT closed following the PM’s statement.
However, news emerged from the government yesterday that throws this into doubt. The article “Jodrell Bank’s e-Merlin network still faces closure in 2028” suggests that the govt still upholds the STFC funding reductions.
In an ApJ paper on ArXiv, Brad Schaefer analyses available data on V1405 Cas and concludes, among other things, V1405 Cas is not a Type Ia supernova progenitor.
V1405 is still mag ~13 and above quiescence.
This MNRAS submission on The First Multi-Messenger Nova: External Shocks, TeV Photons, and Neutrinos in the Next Eruption of T CrB takes another look at timescales for its eruption recurrence.
Taking various factors into consideration, the authors come up with a recurrence time-scale of Trec ≃ 80±12 yr.
However, they note that if substantial weight is instead assigned to the proposed historical eruptions of T CrB, and the 1217–1787 interval between eruptions is assumed to contain seven recurrence cycles, the resulting recurrence history implies a much narrower characteristic time-scale of ≃ 79–80 yr with a dispersion of only ∼ 1–2 yr. The latter is in line with Schaefer’s predictions.
We are now at T(last eruption) + 0.6 years and we keep looking…..
Over the last couple of days on logging in I get the following message:
Forbidden (403)
CSRF verification failed. Request abortedI am nevertheless logged in when I then navigate to the homepage
Just to round this off, here is the processed version of Mike’s early spectrum image taken on 2026-08-25 compared with mine for the same night. They are qualitatively similar with the P Cygni profiles in H alpha, Beta visible at this stage can be seen in both spectra along with various other lines including FeII. The objective prism resolution approaches that of the ALPY at the blue end but is significantly lower above 5500A where the non linear dispersion compresses the scale in the prism spectrum. (Note the Y scale, these features are quite weak)
Cheers
RobinThanks Robin. Interesting to see.
Hi Jeremy,
There is indeed an early Star Analyser spectrum of this Nova posted on “Cloudy Nights” in which the P Cygni profile at H alpha is resolved
Note sure if it can be picked up in Mike’s early spectrum but I will take a look (The resolution in prism spectra is highest at the blue end where the dispersion is greatest)
Cheers
RobinThanks Robin. Good to see.
I see the “logged in” cookies but they are all set to expire at the end of the session (which is why I am being logged out) while others are not.
I have just edited the expiry time on these cookies to a date in the future and I stay logged in
Robin
Aha, that is cunning, Robin. I tried without success in my iPhone and iPad.
AI tells me “iOS Limitations: Apple’s iOS and Safari do not provide a user setting to alter, extend, or shorten individual cookie lifespans or session timeouts.”
But if any iOS users have a work around, let me know.
Is that a P Cyg profile in the H_alpha line in the Tessier spectrum but not from the prism?
Hi Jeremy,
I think it is probably an artefact from the spline fit I used to reduce the resolution down to match Mike’s resolution. There was a P Cygni profile at ~1500km/s in early spectra 25/26 Aug but it was soon engulfed by the emission. Here is H alpha in Francois’ spectra at full resolution. You can see the P Cygni profile in the earliest spectrum (and in my low resolution spectrum from 25th) but not after (The narrow lines are telluric water lines)
Cheers
RobinHello Robin,
ah, that makes sense. Thank you. Yes, I noticed the P Cyg profile in your earlier spectrum.
Would Mike’s prism have sufficient resolution to see the signal when present? Or a Star Analyser, for that matter? – I seem to recall you showed it with P Cyg itself, but I was wondering about novae.
Go well!
JeremyI use several devices to view the BAA web page (phone, iPad and Windows PC) and using Chrome, I’m logged out immediately I close the page. This has always been the case – and it’s really annoying. If there is something lurking behind the scenes causing a ‘time out’ then it’s doing it on all devices, and only for the BAA.
Gary
It’s an odd one, Gary. I too am logged out as soon as I move to another tab (I don’t even close tab) on iPad and iPhone in Safari. Yet other websites retained me as logged in.
But I rarely have to login in my Macbook in Chrome. Which I much prefer.
The spectroscopy database is not designed to take spectrum images and though digitisation is straightforward using freely available software
Here is a “quick and dirty” digitised spectrum off the jpg of the observation 2026-08-31 compared with one from the same night by Francois Teyssier from the ARAS database at much higher resolution so spline smoothed for this comparison.
For wavelength calibration I used a 4th order polynomial based on 8 identified emission lines and since I did not have a reference star for flux calibration, I rectified (flattened) the spectra.
Apart for the strength of the H alpha line which was saturated in the jpg image, the agreement looks good.Cheers
RobinNice work Robin. Is that a P Cyg profile in the H_alpha line in the Tessier spectrum but not from the prism?
Mike,
as I have commented before, you are always welcome to write something up for the Circular tor Journal.
On a broader point, the BAA Gallery is a place to present ones images, and it is good that you do that, but it it not the place to submit observations for analysis because it is not an observational archive. The place to submit VSS observations is the Photometry Database or the Spectroscopy Database. Submitting to these ensures the data are archived properly and available to all.
I can also add that VSS Circular articles (like JBAA papers) appear on the NASA ADS, where they are also available to all. Contributions welcome.
Jeremy
Some promising news breaking
On 27 July, as part of my asteroid occultation work with my remote telescope in Galicia, Spain, I noted an interesting feature in the lightcurve of an occultation by asteroid (8007) of the star UCAC4 354-170588.
Following subsequent analysis and peer review, CBET 5730 has now been published, reporting the discovery of a satellite of the asteroid.
http://www.cbat.eps.harvard.edu/iau/cbet/005700/CBET005730.txt
I’ve attached figures illustrating the event.
Regards,
Michael O’ConnellExcellent work, Michael!
Jim Wild, RAS President, writes:
“The Royal Astronomical Society welcomes an upcoming debate at the Houses of Parliament about cuts impacting astronomy and encourages all Fellows to contact their MPs to urge them to attend.
It will take place on Tuesday 1 September from 1-1.30pm in Westminster Hall.
Last month it emerged that measures to address a devastating funding crisis will put a wide range of UK astronomy projects, facilities and international partnerships under severe pressure.
The recent warning that astronomy at Jodrell Bank Observatory could end has attracted significant public attention, but it is only one part of a much broader picture. Other internationally important programmes are also threatened, such as UK involvement in the James Clerk Maxwell Telescope (JCMT) in Hawaiʻi, prompting serious concern from the RAS about the future strength and breadth of UK astronomy.
The consequences of the cuts are only just starting to emerge, and their impact will also extend well beyond astronomy, affecting other strategically important areas of UK science, including particle physics and nuclear research.
Intense lobbying from the RAS and leading scientists has undoubtedly helped soften the blow for UK astronomy, but the future is still bleak and the cuts so deep that more needs to be done to campaign for a re-think.
The latest analysis of the impact of the cuts across STFC-funded fundamental astronomy projects is 35 per cent, which sits uncomfortably against the headline figure of the 10 per cent budget reduction to projects quoted by UKRI and is much closer to the impacts originally feared at the beginning of the year.
RAS President Professor Jim Wild said: “The Westminster debate is a chance for us to continue to make our case.”
I have written to several of the Cheshire MPs, including the MP for Congleton where Jodrell Bank sits, about Jodrell and the cuts more broadly and have been assured of their support.
I urge others to write to their MPs.
Tampo-san (SAAO) writes:
“PNV J19450648+1822422 was originally discovered by the NMW-TexasTech
survey. Its position coincides with a known eclipsing binary candidate
in Gaia, with an orbital period of 9.9011 d. Thus, time-resolved
observations may reveal eclipses during its decline as the photosphere
recedes.”It turns out that there was a false signal and this is not eclipsing. Sebastian Otero has updated the VSX entry accordingly
Official name of N Sge 2026 is V488 Sge
http://www.cbat.eps.harvard.edu/iau/cbet/005700/CBET005729.txtI’ve just created an object entry for ‘Nova Sge 2026’ in the image gallery, and tagged last night’s images.
It can’t happen very often that there are two active novae at the same time, called ‘Nova Sge 2026’ and ‘Nova Sgr 2026’!
I haven’t created an entry for ‘Nova Sgr 2026’ yet as I don’t think any images have been uploaded, but I will add it if any observations appear.
Great idea, Dominic – thanks.
Yes, much going on in the field of novae right now, what with these two plus N Aql 2026 and N Tau 2026.
