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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:
David – Are you sure that is the best idea? It is a well-known fact that people are a lot less inhibited in bars which is why you don’t often see decent karaoke anywhere else. Perhaps you could do both. A formal concert version and a bootleg B-side bar version.
I would hope they use a standard library (e.g. cfitsio) to read and write FITS files rather than something homebrew. I use cfitsio for all of my code and it is very robust.
It looks as if it is something to do with the data format. A lot of programs can read FP files now (even Astrometrica) but they assume that the data is scaled in the same way as an integer format file, i.e. a range of 0..65535 and they just truncate to the nearest integer. FP format FITS files can have some wacky scalings. I’ve seen some where the entire image dynamic range is in the range of 0.0 to 1.0 and that clearly doesn’t work very well if you just truncate. From looking at the header of your calibrated file that does not look to be the case here.
The headers look OK with nothing obvious. Do you get any hint in the error message from VPHOT or does it just silently die? As a workaround can you get ASTAP to save your calibrated files in integer format? I would have thought that there would be some option to do this.
The file extension shouldn’t make any difference.
Are the files roughly the same size? The raw files you get from the camera are probably 16-bit integer (BITPIX=16). After calibration they may be floating point (BITPIX=-32) and it may be that Vphot can’t cope with that. The FP files will be twice the size of the integer ones. If Vphot can’t cope with FP that is a bit poor but there may be an option in ASTAP to save as ints.
Failing that, have a look at the FITS header and see if you can spot any significant differences. That might give a clue as to what is going wrong.
Sadly, I’ll miss Winchester again this year so you’ll be denied the experience of my G&S baritone but please record this if it goes ahead. It should be a hoot. Something to feature in the next Christmas Sky Notes.
Using astrometry from me (970), Peter Birtwhistle (J95) and Patrick Wiggins (718) obtained since the propellant leak stopped I get a nice fit (3-day arc, 0″.2 residuals) to a gravitational only orbit for the lander using Findorb. This gives a predicted Earth impact time of 23:44 UTC on 2024-01-18 over northern Australia in daylight. The lander is potentially imageable from the UK a few hours before re-entry on the night of the 18th as it moves through Cancer, low down in the east after sunset, although it will be moving very rapidly across the sky.
Just imaged the lander and the Centaur and they are both close to the position predicted by Bill Gray’s site (https://projectpluto.com/sat_eph.htm). The Centaur (2024-006B) is around 17.0 now and the lander (2024-006A) is around 17.6. Astrobotic have said that the mission will end when the lander burns up at the next perigee on January 18.
