Xilman

You are very far from being the first to screw up in this fashion. I speak from experience 8-( I didn't even have the excuse of a source providing me with a poor position when my first attempt to find AE And was half a degree away from its true position. That said, I did manage to image six globular clusters in M31 so the time wasn't entirely wasted. It is always worth going to https://minorplanetcenter.net/iau/MPEph/MPEph.html or https://minorplanetcenter.net/iau/NatSats/NaturalSatellites.html, IMAO, depending on which you wish to observe, Please try again. I am certain that you can find a goodly number of TNOs.

Paul: when was your image taken? The best I can determine from what you have posted is close to 2023-12-01T00:00Z. My estimate is from the file name, part of the path being 11-30 and another being 12-01. At that time the TNO's position was 05:21:31.3 +03:57:07 according to the MPC, which is a long way outside that image. As near as I can make it, by using astrometry.net for putting a WCS on the image, the bounding box of your image is (05:22:25, +03:45:20) (05:23:04. +04:12:00). That is, the Declination covers the range but the RA is too far east. If, on the other hand, that box does indeed correspond to the position of (229762) your image must have been taken on November 14th or 15th.

Right now I don't know the practical short wavelength limit. 1550nm is near infra-red. 29mm is microwave. Atmospheric absorption renders much of that range inaccessible but there are still some usable windows. Light pollution in the IR is negligible but there is rather a lot in the microwave spectrum.

I just came across this link which has interesting content: https://physicsworld.com/a/new-superconducting-nanowire-single-photon-detector-has-400000-pixels/ For instance: “They work for any [photon] wavelength up to 29 mm (not true for many other silicon technologies) and have demonstrated detection efficiencies of 98% at 1550 nm. They also have very low uncertainties in photon arrival times (timing jitter) and have extremely low false detection rates (dark counts).” The technology is still bleeding edge, at least in part because they (presently) require superconductors and I doubt we will see it in cameras affordable by amateurs but it looks very interesting to me. However, liquid nitrogen is (relatively) dirt cheap and progress in high-temperature superconductivity proceeds apace.

As for lighting, when I did visual observing I used a small clip-on red light attached to the clipboard on which I took notes.

I've three. The modern hi-tech way is voice recording. The old fashioned way is waterproof "paper" and a wax pencil. Most anything can be used as a writing surface - a piece of formica, transparency slides (remember them?), plastic chopping boards, ... The really old fashioned way is to call out the observations to an assistance who records them for your. If it worked for William Herschel, ably abetted by Caroline, it should still work today. You might have problems finding an assistant, though speech to text software might be good enough. For either of the first two you still need to transcribe the results in a warm, dry and lit environment.

Not yet tried to find out. I have my doubts.

I downloaded FABADA from https://github.com/PabloMSanAla/fabada yesterday and have been playing with it today. FABADA is Fully Adaptive Bayesian Algorithm for Data Analysis and can be used for noise reduction of both 1-dimensional spectra and two-dimensional images. The results can be astounding! The image below is a 30-second sub of a star field containing (846) Lipperta, one of 63 taken for time-resolved photometry for the BAA ARPS section. With the exception of a few hot pixels, all of the stellar images on the smoothed image are real, as verified by comparison with the DSS2 images. Some are 16th magnitude and a couple of galaxies also show up. If anyone wants to check, point Aladin Lite at 9:14:33 15:41:08

Just took a look at your M81/82 image on your website. I am pretty sure that if you re-processed to enhance stellar details rather than dust and nebulosity you will find quite a few GCs in it. 100 hours is far longer than anything I have ever taken.

Globular clusters much further afield are accessible to amateurs. HVGC-1 (https://en.wikipedia.org/wiki/HVGC-1) is 54M light years away in the Virgo cluster. My image is below. M87 has many thousands of known GCs - hundreds, if not dozens, are visible in long-ish exposures.

See https://britastro.org/observations/observation.php?id=20190311_020000_9a2c47fcf9f3ee97 and https://britastro.org/observations/observation.php?id=20190311_020000_14c9b7973142fb48

La Palma does have the advantage of being 20-odd degrees further south than the UK. That said, I know that some people around here use remote telescopes at southern latitudes. Anyway, the M81 clusters are at a comparable distance, so comparably bright, and M81 is circumpolar from the UK. Well within your capabilities, in other words.

NGC 253 is q starburst spiral galaxy in Sculptor. It is 11.4 million light years away and so is well outside the Local Group. There are at least 82 confirmed globular clusters in orbit around it and a number of candidates which await confirmation. They range in brightness from 18.4 to 23.1 so the brighter members are well within range of imaging by amateurs. This image was 1560 seconds with a unfiltered SX 814 camera on a 0.4m Dilworth. The contrast has been stretched to show the fainter globulars and so the galaxy itself is over-exposed. Some GCs lie outside the field, some are lost in the galaxy, and some are too faint to be visible in this image. I intend covering more of the field and going deeper with longer exposures but that will have to wait. Six confirmed globular clusters (out of a total of 82) are marked. I didn't check for candidate clusters. From the top, they are numbered 148, 146, 139, 109, 168 and 99 in table 3 of A VST and VISTA study of globular clusters in NGC253. by Cantiello et al., Astron. Astrophys. 611, A21 (2018). Their g magnitudes are given as 20.98, 21.00, 20.53, 21.12, 20.32 and 20.43 respectively. Others are encouraged to try for extragalactic globular clusters. Those in the local group are within range of a 20cm scope. The Sculptor and the M81 groups of galaxies certainly with a 30cm. The brightest in NGC 253 is magnitude 18.43 and I've seen an image of M31 taken through a 8cm refractor which reaches that magnitude ...

Can you post some pictures, please, especially of the end with the connector. That may reduce the size of the search necessary. Another approach may be to perform some image searches on the likes of Google. The amount of information given so far hasn't been sufficient to let me find plausible candidates.

Congratulations. You have picked up an individual star in an external galaxy. It is a blue supergiant variable known as Y Tri. I haven't had chance to measure its brightness with any accuracy but guess it is around 18th magnitude. It is fainter than any of the comparisons on the AAVSO chart but I'm pretty sure it is measurable and will report back.

Thanks Paul. It does indeed have a WCS. One of the things I intend to look for is Y Tri, a variable which I intend to add to my program. Paul (the other one)

Paul: could you mail me your plate-solved version of the above image please? I would like to see what else of interest it may contain. A major point of my "off-the-beaten-track" postings is to prompt others into extending their horizons and to push their capabilities as hard as they can. Anyone can, and does, take pretty pictures. Anyone who wants to stand out from the crowd needs to try harder than the rest.

Just to prove that globular clusters in external galaxies are quite easy to image, here is U49 in the Triangulum Galaxy M33. It is magnitude V=16.3 and so well within range of a 3" / 80mm telescope. There are a number of other globular clusters in this image which are easy find if you're interested. Just ask if you would like a catalogue of their positions. Image taken 2020-11-07 but only just processed. 0.4m Dilworth Unfiltered Starlight Xpress 814 CCD camera 1230 seconds (i.e. 20.5 minutes) exposure in 41 x 30 second subs).

'Twas of the good planet Venus .,.

Telescope: 0.4m Dilworth Mount: custom built equatorial fork with FS-2 controller Camera: unfiltered Starlight Xpress 814 camera Exposure: total of 488 seconds in 17 subs. Processed with astrometry.net, SWarp, ds9 and ImageMagick.

Excellent! If you hit more problems, and it's unlikely, let me know and I will see if I can help resolve them. Looking forward to seeing your contributions. BTW, whereabouts in Derbyshire are you based? I was brung up in Long Eaton.

That one was done, of course, for humorous effect though the figures given are entirely accurate. A 0.2m telescope is entirely a reasonable description. A 0.1m might be pushing your luck. I have seen a 0.15m appearing in a peer-reviewed paper in a professional journal where it was noted that the photometry produced by that observer was of excellent quality. The paper was about the most recent eclipse of ε Aur.

Well, https://britastro.org/observations/observation.php?id=20191209_191900_36b00eba365581f4 was liked by a whole bunch of BAA members. That image was taken with a 0.0022m f/1.8 refractor. I seemed to get away with it. Always worth examining images very carefully in my experience. Interesting things are quite often to be found lurking in them. If you see anything in any of my images which I haven't noted, please inform me because it means I probably missed them.

NGC 288 is a globular cluster in Sculptor. Note the 15th-magnitude barred spiral galaxy PGC 3068 near the right edge of the image. Unfitlered 68s exposure with a SX 814 CCD camera on a 0.4m Dilworth.

Pretty pictures sell magazines, whether you like it or not.