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Nice image, Paul. Yes, the sky was pretty decent this morning and I too had some good views in H_alpha.
Jeremy
My daughter and I spent last evening touring the Cheshire countryside looking for good views of the conjunction, which was absolutely beautiful. The attached pic has Beeston Castle in the foreground.
Jeremy
Indeed some pretty esciting data from Nick. Incredible to think we are looking at the secondary effects of a black hole.
Paul, I am not sure I know what is causing these variations. Much of the work on V404 Cyg has been whilst it was in quiescence, where large variations, or flares, are also seen. One idea is that the flares are caused by local magnetic reconnection events in or above the accretion disc. The theory goes that a dynamo mechanism, driven by the strong shear produced by differential rotation, operates in accretion discs, and regions of oppositely directed magnetic fields develop within the disc or between the disc and corona and reconnect explosively. There’s more discussion in the MNRAS paper: http://cdsbib.u-strasbg.fr/cgi-bin/cdsbib?2003MNRAS.346.1116S
However, maybe in outburst it’s something else? I am sure that the current outburst will reveal more – and much of the new data will be contributed by amateur astronomers!
I hope others will get a chance to see such a rare outburst of this peculiar system before it fades.
Go well!
Jeremy
Hello Donald,
A very warm welcome to the BAA! I am sure you will enjoy your membership experience and with the enthusiasm you clearly have, you will find all sorts of opportunities to get involved in observing.
It sounds like you are already well equipped with a telescope and binoculars. The BAA organises Back to Basics workshops, the next one being in North Wales, so not the most convenient location for you in Stonehaven. There are lots of observing sections where your observations would be most welcome. The first question to ask yourself is what do you enjoy observing? You mention you have done some variable star work in the past. This is clearly a field where your observations would be very valuable – and you have eminently suitable equipment to hand. One of the simplest places to start is observing binocular variables. The Variable Star Section’s web site has a page on Binocular Variables here: http://www.britastro.org/vss/chartcat_binoc.htm
The section also publishes a booklet on binocular observing, with instructions and which contains quite a few charts. This is available from Roger Pickard, the Section Director, or the BAA Office. There is a page for “absolute beginners” here: http://www.britastro.org/vss/absolute_beginners.htm
The Section also publishes an “Observing Guide to variable Stars”, available from the BAA Office.
The VSS also has mentors who are happy to help people starting out: http://www.britastro.org/vss/Mentoring.htm
Binoculars and small telescopes are also ideal for observing the brighter comets (drawings and magnitude estimates are always appreciated by the Comet Section) and deep sky objects (again send sketches and descriptions to the Deep Sky Section).
Living in Scotland (if I have the correct Stonehaven) means you are well placed to observe the aurora and noctilucent clouds – the season for the latter is upon us now.
These are only a few ideas and I am sure others can provide info about further sections. And do contact the section directors. They’d be delighted to advise and to receive your observations. Whatever you do – keep asking! The BAA is here to help you further your interest in astronomy.
Go well!
Jeremy
Very interesting, David. What do you intend to do with the gratings?
Thomas Thorp was a BAA member, joining in 1892, and a leading light in the North-Western Branch, in Manchester, where he served as Vice President. A brief JBAA obituary appears in JBAA, vol 24 (10), page 503, October 1914:
We regret to record the death of Mr. T. Thorp which occurred on 13th June last at his home, Whitefield, near Manchester. He was educated at the Manchester Grammar School, and resided in Manchester all his life. He devoted much of his time and attention to the improvement of astronomical instruments. His replica gratings, invented several years ago, brought him into prominence as a pioneer in this department of instrumental mechanism. Many of our members have reason to be grateful to Mr. Thorp for supplying them with prism gratings, applicable to binoculars, which have proved so serviceable in the observation of total solar eclipses. Ho joined this Association in 1892, became a member of the Manchester Literary and Philosophical Society in 1896, and was elected a Fellow of the Royal Astronomical Society in 1902.
All the best,
Jeremy
Hello Alex,
Good to hear about your VS observations.
The VSS spreadshseet automatically converts UT to JD, as Gary says, which is absolutely painless.
If you need to convert UT to JD (or vice versa) at any other time, there is a great Applet on the BAA Computing Section web site:
http://britastro.org/computing/applets_jd.html
This is also linked from the front page of the VSS web site.
Jeremy
A couple of people have kindly asked if I wish to continue receiving data on this star.
My request is that observations are submitted directly into the BAA VSS Online Database. That’s the safest place for them and will ensure they are available to all researchers in the future.
Jeremy
Hello James,
nice to hear from you. There isn’t an online directory. I recall the BAA published a membership list (actually a booklet) in the late 80s or early 90s (I have mine around somewhere). There are all sorts of data protection issues now which I suspect would preclude publishing anything meaningful online.
All the best,
Jeremy
Last year a campaign was organised by the BAA Variable Star Section to monitor this dwarf nova.
A paper summarising the results has been accepted for publication by JBAA and a pre-print is available here: http://arxiv.org/abs/1505.07709
Many thanks to all those who contributed to, and supported, the campaign, which shows just what is possible via cooperation and pooling of observations.
Whilst the official campaign finished in January, observers are still welcome to monitor the star, which shows frequent outbursts and superoutbursts. The supercycle is one of the shortest of SU UMa’s on record, at 67 days.
Jeremy Shears
This is an amazing result, Robin. Having tuned your system to achieve such a faint LM, many objects will now be within your grasp.
Go well!
JeremyHello Mike,
Good to hear about your interest in CCD photometry of variable stars. Indeed there is quite a bit that the modestly equipped observer can do in this field – especially when they combine data with other observers. The objects you mention are popular, partly because these they often have short periods which means you can get interesting data in a few nights. RR Lyrae stars, delta Scu stars and their cousins HADS (High Amplitude delta Scutids) fall into this category. I haven’t done much on these stars as I mainly concentrate on cataclysmic variables, which also have short periods (a few hours). A few of us looked at a delta Scu in Cas a while ago: http://adsabs.harvard.edu/abs/2007OEJV…76….1S. I have to admit the target happened to fall in the same field as a dwarf nova which was our main target!
I would be happy to chat a bit more with you about this topic – if you are attending the Meteor Section meeting in Birmingham on Saturday, that would be an opportunity (whilst talking about meteors as well, of course!).
Go well!
Jeremy
Thanks for highlighting this, Martin. Just listened to it on iPlayer:
http://www.bbc.co.uk/programmes/b05qdw88
In spite of it being only a short piece, 15 mins, it contains a pretty though analysis of Hay’s achievements, by Simon Heffer. And his interest in astronomy is mentioned – along with his white spot on Saturn.
Go well!
JeremyGood to hear that you met with success, Nick. Nice images and well done for posting them so promptly.
I stayed at home in Cheshire and hosted some children from the local Primary school along with their parents. The BAA Solar Viewers went down well. It was clear throughout and everyone had good views through my H-alpha and white light telescopes. A bit warmer than Svalbard, I suspect, but we only got a 90% eclipse – impressive nonetheless.
Go well!
JeremyI had my first naked eye view of the comet last night and it was seen well in 8 x 40 binos.
It’s not often we get to see a bright comet, so I hope others will have an opportunity to look at it.
Go well!
Jeremy
Hello Cam,
those are great images: a nice range of star colours in the Double Cluster and a wealth of detail in M42. I always think M42 is one of the toughest objects to image, given the range of contrast – but you have done a very job job.
You seemed to have tamed your HEQ5 – it’s certainly giving you good results.
Keep up the imaging.
Go well!
Jeremy
I have begun the analysis of the CSS photometry data from the campaign, so I thought a quick update might be helpful. We have 6552 data points from the BAA VSS, AAVSO and CRTS databases, covering the 2013 and the 2014 observing seasons. You can view the 100-day plots for the recent season (data up to 2015 Jan 2) here: http://www.britastro.org/vss/CSS%20plots%202014.pdf
The red dashes are “fainter than” measurements. The blue data are CV or V.
You can see that coverage got better as the campaign took off. The light curve is typical of an SU Uma system (not an ER UMa as once postulated) with frequent outbursts and in my mind is quite beautiful. There are 4 superoutbursts visible, plus many normal outbursts. Analysing the superoutburst times gives a fairly consistent ephemeris, with a period of 66.4 days, taking into account the 4 supers in 2014 and an additional 2 in 2013; or 68.7 days if I only include the 2014 supers. Of course, superoutbursts are only quasi-periodic and it is a mug’s game to try and predict the next. But for a bit of New Year fun I’ll have a go anyway: sometime between Jan 18 and Jan 25, depending on several assumptions – most likely around Jan 23 if I were a betting man. You heard it here first, as they say….
However, given the field is slipping into the west, it will be a challenge to spot the next superoutburst, but it would be fun to try – and would help to update the ephemeris before the seasonal gap. So single shot imaging of the field would be helpful (as would short photometry to look for confirmatory superhumps). The supers last about 13 days.
Of course, this analysis makes use of the hard-won data submitted by many observers – hats off to them! I have used data kindly contributed by: David Boyd, James Boardman, Juan-Luis Gonzalez Carballo, Ian Miller, Ken Menzies, Roger Pickard, Gary Poyner, Richard Sabo, Pavol Dubovsky, Richard Sargent and Denis Buczynski. If you have observed this star and your name is not listed, please contact me as it probably means I have not seen your data.
Good luck and go well! Jeremy
Great work, Bill. Fascinating to see the results you are obtaining. Hopefully we’ll soon get some multi-station captures of the same event, to tie in with your spectroscopy.
Go well!
JeremyThat’s an interesting project, Mike. And nice images. Hope you will continue to extend the gallery.
Go well!
Jeremy
Hello Cam,
good to hear from you. I am afraid that I do not have experience of that telescope, but perhaps somebody else does.
Personally I have always found small refractors to be good for wide field imaging, given their compactness, no need for collimation and ability to use relatively small mounts. I recall from your previous postings that you have used an ED80, which was giving you excellent results.
Anyway, I hope to see some further results from you with whatever telecope you use.
Go well!
Jeremy
