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A response to this question posted on comets-ml pointed to a Cloudy Nights discussion from last month which had a plausible explanation which was that the orbit of 13P was better known than 12P so it was very quickly recognised as a recovery when Brooks found it on the return.
https://groups.io/g/comets-ml/message/32292
https://www.cloudynights.com/topic/920186-the-name-of-the-comet-13polbers-problem/#entry13436144Well, if we take Ireland as being 500 km long and the nearest Mars comes to the Earth as 60 million km then the flag would subtend around 500/60E6 = 8 microradians or about 2 arcsec so a Martian Damian Peach would definitely be able to resolve it.
Blimey. All that advice and only a day to get your telephotographic gubbins together and haul it up onto the roof of Selfridges along with a friend to help you get the focus right. Am I correct that he is recommending focussing without a filter as long as the “magnification is very high”? Also looking directly at the Sun through the finder tube to line the camera up. Health and Safety clearly wasn’t much of a thing in 1912. I doubt if they had high railings around the roof either.
I was up in Greenock but my meteor cameras in Chelmsford recorded the aurora.
One hour timelapse from NW colour camera: https://nickdjames.com/aurora/20240510/auroraNW_20240510_2300_ndj.mp4
Full night timelapse from N mono camera: https://nickdjames.com/aurora/20240510/UK004D_20240510_201747.mp4
Full night timelapse from NW mono camera: https://nickdjames.com/aurora/20240510/UK004G_20240510_201839.mp4
Full night timelapse from SE mono camera: https://nickdjames.com/aurora/20240510/UK004E_20240510_201811.mp4
Full night timelapse from SW mono camera: https://nickdjames.com/aurora/20240510/UK004F_20240510_201825.mp4
Full night timelapse from zenith mono camera: https://nickdjames.com/aurora/20240510/UK004H_20240510_201845.mp4It was indeed. The Beacon was a brilliant venue thanks to Marion and Inverclyde, Involving the choir in a music-themed meeting was inspired, great speakers, lovely weather and a spectacular aurora on the Friday night.
The other highlight for me was seeing PS Waverley steaming off up the Clyde from her berth at Greenock with a loud burst on the horn during Alec Mackinnon’s talk. The attached pic shows the view we had out the windows from the lecture room. I’m a sucker for anything steam powered and she must be one of the most beautiful ships around.
Indeed. Amazing views over the Clyde from up in in Greenock. No camera with me so visual only but a really colourful, bright and dynamic display all over the sky. I can see that it was a really impressive display back home in Essex too. A great start to the BAA Spring meeting weekend!
Mike,
Here’s an example from one of my meteor cameras with R Lyr marked. This is an average of 256 video frames (at 25 fps) using an IMX291LQR based camera with no IR filter. The Bayer matrix on these cameras is designed so that all the pixels have a passband at IR so the chip is effectively a mono sensor in IR. This is one of the problems of trying to use these meteor cameras to monitor variables.
Nick.
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That is absolutely bonkers. So some people have ended up with free Seestars. I hope Amazon end up paying for this rather than the vendors.
It seems that total eclipses induce a kind of temporary madness in a large number of people. It must be something to do with those extra UV rays during he partial phase.
I’ll be attempting to image 12P during totality. At 4th magnitude it should be fairly easy. At the 2020 eclipse I got C/2020 S3 (Erasmus) which was fainter (5th mag) and closer to the eclipsed Sun:
https://britastro.org/cometobs/2020s3/2020s3_20201214_1610_ndj.html
The trick will be to take lots of frames during totality, calibrate them with some very good flats and then stack them.
Seeing the comet visually will be very challenging. The sky will be fairly dark at this eclipse since the shadow is broad but it will probably be the equivalent of the western sky at the end of civil twilight. I’ve seen numbers such as 13 mag per square arcsec quoted. Think how hard it is to see a 4th mag comet in a very light polluted sky (say 16 mag per square arcsec). I’ll certainly be having a quick look with binoculars though!
Indeed Steve, that is total BS written by someone who has clearly never seen a total eclipse so I think “reputable author” is rather kind. The surface brightness of the inner (K) corona is about 1 millionth of the surface brightness of the photosphere so similar to the surface brightness of the Full Moon. There is lots of very bad advice out there about looking at the totally eclipsed Sun. This is particularly awful:
https://jamanetwork.com/journals/jamaophthalmology/fullarticle/2816113
To quote: “It is not safe to view a total eclipse without added eye protection, even during the 90 seconds when an eclipse is total”. If people follow that advice on April 8 they won’t see much!
To be clear, during totality it is perfectly safe to view the eclipse with any optical aid you wish to use and no filters. I have always watched the 2nd contact diamond ring with the naked eye then switched to binoculars/telescope for totality and then gone back to naked eye as soon as the chromosphere appears just ahead of 3rd contact. For photography/video I’ve taken the filter off a minute or so before second contact and put the filter back after third contact. I have never had any sensor damage from doing that (although your experience may be different and I take no responsibility etc. etc.). My video from last April is here:
https://www.youtube.com/watch?v=QmoSTGQ6hpE
and it shows prominences and the inner corona for around a minute before and after totality.
That is very odd. I haven’t been able to find why they think it is an asteroid. At mag 13 it is either huge (in which case it would have been discovered already) or very close (in which case it would have a large apparent motion unless it is heading straight for us). There is nothing matching it on the NEOCP (the brightest object there is 18.2. It is possibly AI gone mad but there is a long list of real people on the discovery report.
It will be interesting to see what this turns out to be. Possibly a subject for my next Christmas Sky Notes.
The comet is showing a fairly bright ion tail to the north but its length depends very much on sky conditions since it has a low surface brightness. The current total magnitude is around 6.6 so it should be approaching naked eye visibility at really dark sites. In a 9 arcsec radius the magnitude is around 10.4 and this is a bit above the trend for that aperture. It looks as if there have been a couple of small outbursts in the last week.
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It is very close to the Horizons prediction and around mag 12 at the moment (Feb 15.95). It’s been almost total overcast here tonight but I managed to get a few images in small gaps.
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This is usually a good source of re-entry predictions too: https://aerospace.org/reentries.
James – The discussion was streamed as part of the SGM. The video is online here:
https://www.youtube.com/live/-ARFP-FBl98?si=4dGJXXjJV23UHccI&t=173
According to this thread from six years ago:
https://www.aavso.org/reducing-fits-size-use-vphot
Vphot has an upload file size limit of 50 MB. That is probably why your attempt to upload the FP images fails since the filesize is 65 MB. I would have thought that it would tell you this rather than failing silently.
I doubt very much that a few singing astronomers will rank very highly on that bar’s rowdy meter. It’s a student bar for farmers…
And we now have a confirmed meteorite find from this impact:
