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Seconded, though it affects me a little less because I tend to leave the tab open 24/7. That’s feasible on a desktop machine in a private home.
Hi Dominic
I’ve mentioned this before but it bears repeating. As this text is being entered I am helpfully informed You can use BBCodes to format your content.
There is no indication what BBCodes are, nor any obvious way of using them.
IWBNI we could have a few buttons which, when pressed, underlined the selected text, inserted a hyperlink and so on.As you can see, I have memorized a few of them …
Added in edit: even then, I was unable to work out how to use the [ URL ] tag properly.
You’re welcome.
Now wondering if that sort of very detailed TS photometry could be used to predict the time of an imminent outburst perhaps to within a few hours. I doubt many people have tried to do it before.
Eclipses No(s): 27, 28
State: Quiescent
Data Quality: Good (check star sigma = 0.045)Holy cow. What’s going on here? I thought there was something wrong with my telescope.
How do you measure the bright spot here? I assume the quiescence is somewhere in the middle of the chart, at 16.89 mag, and the bright spot before the second eclipse pushes it all the way up to 16.75 mag – an amplitude of 0.14 mag. Note two-step increase in brightness in the orbital hump – first to 16.85 mag, then the second one to 16.89 mag.
The profile is a new type, U/H/A, never seen before. It is similar to U/L/S, except that here we see a very prominent bright spot.
Lots of flickering – at the bright spot apperance, orbital hump, at the minimum, and the egress. Note the post-egress 0.05 mag dip, then sudden rise of 0.1 mag, then ~ 0.5 mag dip. Flickering? I don’t think so. Exactly the same structure is visible in both eclipses tonight. Is this the second bright spot or, perhaps, stream overflow? Could the second bright spot/stream explain the 2-step rise, and the post-egress hump?
LOTS of questions.
Max
I have been following this thread with interest and the quoted post, expressing a degree of incomprehension over the star’s behaviour, prompted me to contact an old friend, Phil Charles. Phil is a notionally retired but still very active professional astronomer who has specialized in the study of CVs of various types. He has given me permission to pass on his response.
Have to confess I’m not familiar with CG Dra, but that’s a very good light-curve for an almost 17th mag star (as expected for a 0.4m telescope in presumably a good site). It’s an eclipsing U Gem-type dwarf nova, here in quiescence, but I just looked at the AAVSO long-term light-curve and you can see that it outbursts quite frequently. That means it will be undergoing continuous mass transfer from the donor into the disc, and that displays itself as enhanced light when viewing either side of eclipse by the donor. In fact the hump here is quite broad, so it’s definitely an active system, and it’s clearly growing the disc in preparation for its next outburst.
Given the obvious data noise that is also visible in the comparison star, my reaction is that there’s nothing that unusual here. Let me know if you think I’ve missed anything.
Additionally, use
Just checked the neighbourhood of my observatory.
I very much believe that a large area to the SW of me is now Bortle 6-8 rather than 4-6.
A very old saying: be careful what you ask for in case you get it.
8-(
Asking on behalf of a friend, does anyone recognise this observatory? It is thought to be in Australia.
https://collections.museumsvictoria.com.au/items/774306 gives as much as I have been able to find.
Definitely Australia, probably Victoria, possibly Bendigo. Circa 1900.
Not sure whether this somewhat elderly thread is still current or whether I should start a new one.
Over on SGL members were asked about their smallest telescope. Ever the pedant and firm believer that one should never ask for anything unless you are prepared to receive it, I pointed to an image taken with a 2.2mm f/1.8 refractor. This one to be precise: https://britastro.org/observations/observation.php?id=20191209_191900_36b00eba365581f4
Now I am pretty sure when it was uploaded originally to the old gallery it was displayed upright and not sideways. Can it be fixed, please?
No idea whether other images have been similarly rotated.
Already mailed my wants to David.
I also have a few duplicates, so between us perhaps we can make a more complete collection for anyone else interested in building up a library.
Hmm, I can’t see how to direct message you from the forum interface. He is in Breaston, about 8 miles away from Nottingham.
Please drop me a line at my firstname.surname (at) gmail dot com for his full address.
Now arranged. Thanks James.
Incidentally, how does one send a private message to another member? Anyone know?
Hmm, I can’t see how to direct message you from the forum interface. He is in Breaston, about 8 miles away from Nottingham.
Please drop me a line at my firstname.surname (at) gmail dot com for his full address.
There is no need to postulate expansion of space in order to explain redshifts greater than one, in fact you get z=1 for a velocity of just under 180,000 km/s which is quite modest and probably will be achieved by human artefacts[sic] sometime in the next few thousand years.
I am not sure whether you consider tightly collimated clumps of electrons, positrons and protons as “human artifacts”. I do, because they do not occur naturally as far as I know, especially those of the positron variety.
If you do include such things, we achieved such velocities many decades ago.
If it had the maps, I suspect £1000.
But it doesn’t, so my question remains.
And while I am on the subject: a preview-before-posting button would be nice too. Four edits in my earlier post could have been avoided …
We are told that BBCodes can be used to format our postings. I am one of those (very few?) weird people who have memorized a few such codes, such as [_i] [_/i] (underlines added for clarity) for italicizing intermediate text. I doubt that there are many other oddities like me. So, two questions:
1) Would it be possible to provide a pointer to TFM for BBCodes for easy reference when posting and/or replying?
2) Is it possible to provide buttons for pointy-clicky encoding of regions of text such as many other fora provide? See http://www.mersenneforum.org for an example where I post rather often if you want to see what I mean.Thanks Andy.
I have no issues at all with the auto-logout feature — I have been professionally employed in the IT security business for well over 30 years — but the other is a WIBNI which could well take time to implement but would also be valuable if it can be done.
The site logs me out after a period of inactivity. That is mildly annoying but nothing more.
What is annoying is when I am logged out when the Forum page is displayed. To contribute I have to re-authenticate (fair enough) but after doing so I am not returned to the previously displayed page.
Can this be fixed?
I don’t (yet) use ASTAP but thanks for drawing it to my attention. I will take a look.
Russ Laher’s Aperture Photometry Tool, APT, is my tool of choice. Written by a professional at the ZTF for professionals and amateurs alike it does a very good job very easily. It produces CSV format output which is easy to convert to a BAA-VSS spreadsheet. A script to do just that is available from me on request.
APT is available from https://aperturephotometry.org/ and there’s a Wikipedia article at https://en.wikipedia.org/wiki/Aperture_Photometry_Tool
A particularly nice feature of APT is that the apertures can be elliptical, so tracking errors can be tolerated better than with purely circular apertures.
For plate solving I use a local installation of astrometry.net with the Gaia DR2 catalogue.
As Comet Section director I like planets that look like comets…
I like comets that look like planets 😉
Most of the small junk out in the solar system like Caliban, Nereid, Quaoar and Makemake would be brilliant comets if they came close enough to us.
