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Please keep up observing and the pattern matching.
It seems very likely to me that outbursts are somewhat predictable, it is just that we don’t yet know how to predict them with much reliability.
Implementation: extra mass, cost, complexity and failure modes all have to be weighed against the benefits of adding them.
Not worth it, in other words.
Oh no, not again. You can not be Sirius!
Get your popcorn ready. This should be entertaining when the other astrophysicists start laying into it. (Though the claimed 5.1σ is interesting.)
I found that but haven’t reported it. Earlier today I found some broken image links, which I have reported. You may wish to check the links in your own pages.
TLDR:
Oh my God! It’s full of galaxies!
Water, water every where but nor any drop to drink.
An elliptical galaxy is almost invisible because it doesn’t have any dust.
Two stars in a ring nebula: you can not be Sirius!
Galaxies sneak into the zone of avoidance when they though no-one was looking.Now to track down the Patent number …
I have not yet found the patent in the WIPO database but this link turned up
Looks like my telescope may well be from the Royal Navy. If so, it would be nice to find out which ship to which it was fitted.
Hi Paul & Alan,
I will be restoring it though it may take me some time to clean and remount it.
There are a few inscriptions, the easiest to read being “TURN TO CHANGE POWER” and “TURN TO FOCUS”. Part of the latter is visible in the image above. Neither of these give much clue to the provenance.
You are quite correct at suggesting Ottway & Co. however, It is fairly easy to read, though the black paint needs renovation, “GUNSIGHTING PATENT V.P. <illegible> W. OTTWAY & CO. LTD EALING 1912”. Another inscription is “PATT. G328Y” and a series of numbers “5 7 9 11 13 15” which are undoubtedly the magnifications available. The only other inscription is “W A/T” where the W is twice the height of the A and the T, which themselves are spaced vertically with a horizontal bar.
It is possible than <illegible> may become readable with some careful photography under oblique lighting and with image processing of the result.
Now to track down the Patent number …
It is possible some prefer not being left logged in permanently
On some fora I frequent it is possible to remain log in and and also possible to tell the browser not to save the credentials. That would appear to satisfy both camps.
Sorry, always have something more to say after I hit the “Send” button (and there’s no “Edit” anymore for some reason).
Yes, this is something else I would like to see. It is possible to edit for a short while after submission but quite a few times the edit functionality times out to early for my liking. It would appear I am not alone.
Could the period be extended to, say, 24 hours?
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.
