Xilman

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.

I am very slowly building up a collection of images of globular clusters, both in the Milky Way and around external galaxies. Here is M14 in Ophiuchus.

I had a similar issue until I bought an observatory in La Palma with the scope under a dome and almost entirely computer controlled. I can do imaging in relative comfort and from inside the house if I want to. These days I live in LP for half the year, in three month sessions. When in the UK (like now) I have a 25cm Dobsonian which gets no use because I am just as apathetic about observing as before but maintain my interest in astronomy by processing images taken in LP. Although I am not suggesting that you go out and buy a physical observatory, but have you considered using remote robotic telescopes? You could choose one in the southern hemisphere which would let you observe things to which the likes of me are impossible.

Images of star trails are very commonly seen. They are generally taken with a stationary camera and use the Earth's rotation to let the sky and stars drift past the camera. This one is different. It uses a moving camera to follow the sky and it lets the star drift past the sky. Barnard's star has an enormous proper motion of 10.3 arcseconds per annum. The stack of subs in the image shown above started on 2019-08-30 and ended on 2023-08-07 for a duration of just a tad under four years. The star had moved 41.2 arcsec in that time. To put it in context, that is roughly the apparent size of Jupiter.

It generally means a groove around the barrel into which the end of the screw which holds the eyepiece to the drawtube fits. If the screw comes slightly loose the end of it is still inside the groove and the eyepiece won't drop out. If the barrel is completely smooth the eyepiece also becomes slightly loose and can fall out, a possibly expensive circumstance.

It's astounding! Time is fleeting! The clouds have broken, at lest partially, and the sky is more transparent than I've seen it for months. I can walk around purely by starlight and that from the Milk Way - no torch required. Making the best of it while I can.

You may have problems but here on a sub-tropical island the cloudy season has set in. Clouded out for several nights now with no end in sight. The rainy season starts in a week or few and runs to November or later. At least folk in the UK don't have to clean abrasive volcanic grit off their optics and out of their mounts.

ITYM nuclear fusion,

Just bought a copy.

Yeah, the Universe was created by the Flying Spaghetti Monster. His Noodly Appendages have ensured that all observations are subtly manipulated to confirm with the current scientific dogma. How can you tell that I am a Pastafarian?

That is my experience too in La Palma - which is technically Spain but geographically North Africa. I get more clear nights (not the last three though and likely not tonight judging by the clouds building up) but much more Saharan dust which really fouls up contrast and reduces minimum magnitude. England, being so much wetter, generally has nights which are much more transparent because all the rain washes the crud out of the atmosphere. It just has fewer clear nights (as distinct from transparent nights) than La Palma. This last couple of months we've also had a lot of smoke from wildfires, first in La Palma and now from Tenerife which is over 100km away from here but the air still smells of smoke. My take: everyone always complains about something. It is human nature. Offer them free beer and they complain because neither wine nor cider is on offer.

You don't operate one without special relativity. Things get heavier as they move faster, so they are harder to bend round corners with magnets, the strength of which have to be altered accordingly as the particles are accelerated. The particles travel at essentially the speed of light when they are at high enough energy so to know where they are, the timing of the accelerating pulses of energy requires SR once again. These are only two examples. Designing and operating the detectors provide more.

In that case we very strongly disagree. The professionals do not have anywhere near enough telescope time to measure everything of interest. Just one example: timing exoplanetary transits is almoe entirely performed by amateurs and yet their results are vital for planning future satellite missions. There are many other fields in which amateurs play a vital role because professionals just do not have the resources. Please report your measurements to the relevant organization(s).