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I wonder if T CrB will go into history as the variable star equivalent of comet C/1973 E1 (Kohoutek)?
I wish I’d seen it. One of the disadvantages of observing from indoors!
Alex – The whole point of the propellant dump was to avoid creation of space junk. It ensures that the stage did not break up due to tank overpressure and, in any case, the stage de-orbited into the Indian Ocean.
I have a CGE which, I think, is similar to the CGEM and get these messages every now and again. It is usually the RA/Dec cables between the mount controller and the motors which are pretty rubbish. If you disconnect/reconnect the connectors it often works or give them a spray with some switch cleaner like Servisol. I think it is unlikely to be the main board. Much more likely to be a bad connection somewhere.
Yes, Saturn set at around 1825UT and Mercury at around 1900UT so it must have been something else. When looking for Mercury I’ve been fooled by distant aircraft which can remain apparently stationary for a long period.
Here’s the video from my UK004D camera which points NW. The hazy sky was brightly moonlit but the re-entry is detectable as a faint object emerging from the tree at the bottom left. It brightens and leaves a strong ionisation trail but there is no sign of breakup this early in the track.
https://nickdjames.com/Spacecraft/2025_022Y_reentry/UK004D_20250119_0343_ndj.mp4
This is the re-entry prediction:
https://aerospace.org/reentries/62878
The stage should have been actively de-orbited from its very low orbit (around 300km) but actually decayed naturally in an uncontrolled way. The COPV tank seems quite robust and has survived re-entry previously so one more thing to worry about.
The madness has already begun. Stories written by journos who don’t really understand orbital dynamics and probability and headlines attached by sub-eds to maximise click-through.
Apparently, if you live on the Moon, you should now be very afraid:
https://www.independent.co.uk/space/asteroid-heading-earth-2024-yr4-moon-china-b2696593.html
This is at the less sensational end of the spectrum. Google will bring up others.
This is all based on some reasonable statements from David Rankin that have been mildly sensationalised in New Scientist and then got the full treatment in the “popular” media.
The word “inconsistency” has negative connotations which don’t apply in this case. Each section can decide how it wants to make its material available. In the case of the Comet Section I get and share observations with groups around the world and contributors to the Comet’s Tale are a mix of members and non-members. For Journal reports I do prioritise observations made by members and most of the images I use to illustrate those reports will be from members. Where appropriate I encourage contributors to join the Association to support the work we do.
I’ve posted an animation of some of the C3 frames from today here:
https://britastro.org/observations/observation.php?id=20250114_211401_cc96625da78ff2ec
Yes, the comet is looking very healthy at the moment. Hopefully it will put on a good show for southern observers when it emerges into a darker evening sky.
The public LASCO images have overexposed the comet. Here is the same image taken from a level 0.5 FITS file and processed more gently. It is a spectacular tail.
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That’s not quite fair on the robots!
The first link refers to SN 2023tyk which went all the way to spectroscopic confirmation without human intervention:
https://www.wis-tns.org/astronotes/astronote/2023-265
The second link is to AT 2024agoh which is a transient candidate with no spectroscopic confirmation. Certainly whatever AI/ML algorithms they are using needs to be a bit smarter and check more catalogues.
Give it time and AI will take over the world. Our current government certainly thinks it is our saviour.
If it is clear tomorrow (Sunday) morning and you can get to somewhere with a flat SE horizon it is worth trying to pick the comet up. It rises around 40 mins before sunrise at 51N and, given that it can be imaged in the daytime, it should be reasonably easy to pick up using a camera. From here (Chelmsford) it will be 6deg altitude at sunrise around 8am. My forecast is clear until 5am but then cloud.
Visual observations will be much harder but please report if you try.
Yes, it is. I imaged it this afternoon in daylight from Chelmsford:
https://britastro.org/observations/observation.php?id=20250111_181128_a9e9cf292d6b6418
The elongation was less than 8 degrees so you need to be very careful.
Thanks for the reminder Tim. At 2am it was -3C out at the telescope but I was indoors in the warm. I got videos of the Merope and Alcyone events. From Chelmsford these were at 02:02:23.40 and 02:43:40.95. Lunar occultations of bright stars are always fun to watch.
Yes, if you’ve every been there the big public car park is close to all of the TV antennas on the right of that shot. It is then a fairly short walk to the 100-inch dome.
This was Mount Wilson a few minutes ago. I think that is the Hooker dome and the Solar Tower to the left.
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It’s very close to Mt. Wilson Obsy as well. Hopefully it won’t be another Mt. Stromlo. The damage caused by the various fires in very familiar places around LA is immense.
I use this 100Wh Li-ion battery pack to power my portable setup:
https://www.amazon.co.uk/dp/B06Y5G3C8Z
It only weighs 0.5 kg and it has 5V USB and 9V regulated DC outputs and a 12V unregulated output direct from the internal cells (which I think are LG 18650s). 100Wh is small enough to take on a plane as cabin luggage but it is large enough to power an AM-3 and an ASI camera with cooler for > 5hrs.
Since the 12V is unregulated it drops below 11V at around 50% capacity so I use an in-line DC buck converter to boost the raw voltage to 13.8V. With that, the AM-3 and camera are happy through to around 90% discharge. You wouldn’t need that if you are using the 5V or 9V outputs.
Martin – Here is Saturn for 2025 with DS included. We should be able to squeeze this in next year’s HB. The combination of DE and DS nicely shows the period between the end of March and mid-May when we see the unilluminated side of the rings. Unfortunately this will be very hard to observe since Saturn is at conjunction on March 12.
The 2025 HB is the first one to use my ephemerides for the planets. I think everything is correct but I’d appreciate comments if anyone finds any errors.
I foresee a very vigorous, not to say rancorous, debate over whether J2000 is kept in perpetuity or whether we move to J2050 within this decade.
Historically celestial coordinates have been defined in terms of the Earth’s mean equator and orbital plane at a particular epoch but we now have the ICRF which is based on VLBI measurements of objects in the distant universe. The ICRF is supposed to be completely decoupled from the Earth’s rotation and its motion but its coordinate axes are (almost) aligned with J2000 for convenience. Adopting a new epoch, such as J2050, would break that close alignment so I can’t see it happening.
Given that (most) people seem happy to decouple civil time from the Earth’s rotation I don’t think that it is a particularly big deal to do the same with equatorial coordinates. Anyone who needs to can precess a position to any date they want and the benefits of having a fixed celestial coordinate system significantly outweigh the drawbacks.
It so happens that, as VLBI measurements get more precise, it seems that there are still some dependencies on the Earth’s motion in ICRF (secular changes in aberration due to our motion around the galactic centre for instance) so we haven’t quite managed to eliminate our Earth-centred view of the universe from the celestial coordinate system as yet.
