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The green glow from the coma, presumably Swan band emission from C2 in that image is interesting. This is of course very typical of most comets but spectra taken on approach suggested it was very deficient in C2 relative to CN. See page 9 of this paper
https://arxiv.org/pdf/2509.01647
The ratio may have increased since though, as happened with 2I/Borisov. (I would love to try for a spectrum but the weather here has been hopeless the past month or more with little sign of improvement)Cheers
RobinBob King does confront this nonsense in an amusing way in his S&T newsletter article. (click out and back in if you get a “subscribe” pop up)
https://skyandtelescope.org/astronomy-blogs/explore-night-bob-king/all-eyes-on-interstellar-comet-3i-atlas/?utm_source=cc&utm_medium=newsletterRobin
If these images are processed by separating the comet from the star background, processing each one differently, possibly with some clever, statistical noise reduction and then putting them back together then using statistics or AI to remove the satellite trails is just another step.
Not science though without the raw data and enough details of the processing steps to allow others to reproduce it.
I normally park in St John’s multistorey
Swan St, Cotton End, Northampton NN1 1HA
https://www.westnorthants.gov.uk/car-parks-west-northamptonshire/council-car-parks-northampton-town
5 mins walk and just £2:20 for the day on Saturdays“T CrB can never become a SNIa”
Never is a very long time. Even if the net accretion rate remains negative, the companion star will also eventually evolve into a white dwarf producing a double degenerate system. The eventual merger of such systems could produce a supernova explosion and is increasingly considered to be the cause of the majority of type Ia supernova explosions.
Robin
A test would be to take images with the telescope rotated to different angles (but with the camera orientated the same relative to the horizon). If it is atmospheric refraction the red and blue areas will always be top and bottom relative to the horizon. If it is the telescope, they will move to different angles relative to the horizon
Cheers
RobinThe trouble is that 25lx at street level is often accompanied by vast amounts of light going upwards and outwards. This means that 10km away in the national landscape there is a gigantic light dome filling about half the sky and at least as bright as a local floodlight.
Indeed and this guidance specifically condones this. I can perhaps understand why levels of lighting might vary between zones but cannot understand why they consider higher percentages of upward flux acceptable in more light polluted areas. Table 7 for example makes no sense. Why should 35% upward flux be considered acceptable for amenity lighting in zone E4. I see no reason why the fraction of light emitted upward should not be controlled to the same extent everywhere.
I dont get the idea of zones at all. Good lighting practise is the same if your are in a dark sky site or the middle of a city. This guidance effectively says if you are already in a light polluted region go ahead and put up more crap lighting. (tables 4, 6 ,7)
I’ve also just updated the item on C/2025 A6
month typo in the last line on that page
(we really need a PM button on this forum)
Reflectors in space could make solar farms on Earth work for longer every day. Is this a sensible idea?
https://www.space.com/reflectors-in-space-increase-solar-farm-capacity
Sensible or not it looks like it may be set to become a reality with a demo to be launched as early as next year
https://skyandtelescope.org/astronomy-news/new-kind-of-satellite-could-damage-eyes/NOTE the forum is not attributing the quote correctly. It was from Howard’s post 621451 here
https://britastro.org/forums/topic/dark-skies-and-satellites-in-the-news/page/2#post-621451I very much doubt that anyone here is a kid,
You never know who is eavesdropping though. Google has already indexed this thread
(I see the forum software has attributed the quote to the wrong person for some reason)
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ARGOS ?
I picked up a couple of cheap dumbbells in the Aldi middle isle a good while back. They did nothing for my pecs but two of the weights have been on my EQ6 for over 15 years now. (The hole is oversize but clamping between two standard weight with sticky backed velcro has held them in place.)
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Hi Paul,
ZTF show it as of yesterday at 13.6 g, 13.1 r
https://alerce.online/object/ZTF25abbgajqCheers
RobinA comparison of the current spectrum with one in the low state March 2024
https://britastro.org/observations/observation.php?id=20250810_221150_5f858c960a245997Cheers
RobinSo no detectable gas. (The positioning of the label in fig 2 indicating the band where CN should appear is unfortunate. At a casual glance it looks like the hot pixel there is a signal. Given that they took 6 spectra it is surprising they did not remove them)
Proper motion confuses the heck out of some of the bots auto reporting transients. They compare the sky with their library image, looking at the differences and once the proper motion moves the star out of the psf of the library image it suddenly triggers a bright transient ! There are quite a few examples in the Transient Name Server
If you look at the image cutout at SIMBAD
https://simbad.cds.unistra.fr/simbad/sim-basic?Ident=ZZ+PSc&submit=SIMBAD+search
and blink between the DDS and SDSS images you can actually see the position move between the two survey dates. The J2000 position is between the two (Sometimes for high proper motions you even see a double image Red/Blue in the colour DSS images because of the difference in dates)
