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Eamonn Ansboro has been a keen observer of TNOs and John Saxton has measured a rotational lightcurve too.
The orbits of the brighter ones are well tied down and very few bright ones are discovered.
I’ve done the latest list for the 2022 Handbook and since 2014 only one bright TNO in the Top 25 has been found, namely 2018 VG18.
Of course the most effective thing that amateurs can do is to observe stellar occultations by TNOs.
Richard
What a shame it was cloudy here.
My wife was gardening and the sounds were unmistakable as they went on for nearly 10 seconds she reported. Sadly looks to have undergone a watery end in The Channel. Thanks for everyone’s contributions.
Denis – From the composition it will be possible then to come up with some answers. Such small meteoroids have a high chance of being fragments from a collision in the not so distant past. Knowing its orbit is really helpful – so it had an aphelion at the outer edge of the Main Belt and so would have been ejected from that region to become an Earth-crosser.
Primitive CCs are chemically modified by contact with liquid water. The samples collected so far have escaped this fate. Covid or no Covid a special effort should be made today to find more!
Thanks Andrew.
I see that Buil comments: “For normal camera use it is mandatory to select the « Even illumination » option (accessible also from the ASCOM interface). If you set this option on, the gradient disappears – in this situation the Atik Horizon camera works properly ” Wayne’s images have a vertical gradient to the background, especially when flatfields are generated, which have short exposure times. So turning off this strange progressive shutter is absolutely essential if photometry is the purpose!
Thanks Paul for flagging this unusual asteroid and the S&T article, which is nicely written.
This object is stable around L4 for a few thousand years at least but looks to be moved around by interactions with Venus. The observational arc is still rather short whilst it is now heading for low solar elongation and has not been observed for over 3 weeks so at almost 22nd magnitude it looks to have moved out of range for a while. Somebody commented on FaceBook about the ‘XL5’ part of its designation – it shows their age or their interest in ‘Fireballs’ !
Wow Dominic – What a transformation! Well done!
I couldn’t believe it when I started playing with what is now searchable. Several tens of thousands of comet images for instance. I had been planning on researching Comet 29P coma morphologies over the years’ of observations but have kept putting it off because of the laborious prospect. Now, in principle, anyone can trawl the Comet Section archive and get involved in that type of study. People may be willing to volunteer to measure images as part of a team effort since these image data are now available and downloadable to all members.
Sheridan – A quick look tells me that from an historical perspective there is only mention of two time-related events happening since 2000 namely European Summer Time Act in 2002, and MSF Rugby to Anthorn switch in 2007. I think more can be written about a few significant changes since then. But that needs some researching to identify what that might be.
Just checked:
The G-band photometric uncertainties in EDR3 are ~0.3 mmag for G<13, 1 mmag at G=17, and 6 mmag at G=20 mag.
In Data Release 2 from 2018 April, uncertainties were ~1.0 mmag for G<13, to around 20 mmag at G=20.
So that is a big improvement!Great excuse to open the champagne – I trust you enjoyed it!
Seriously – I see it is the ‘Early’ EDR3 that is released rather than DR3. Am hoping the photometric data is a big step-up from DR2, which itself was remarkably good. I just heard from the podcast that this will be the case – am thinking of switching to G magnitudes as standard in future work since this is a very good match with unfiltered observations and for comets and asteroids it makes for a very good match. We can always convert to some other photometric system if we know the relevant colour index. Great news.
Object ALCHEMY looks to be too difficult from the UK.
Have looked at all the passes during the coming 10 days and none look to be
practicable.
The sky will not be dark enough for the early evening passes around 16h-17h
and the later ones will be unilluminated and a few ‘000 km distant. They
also tend to be low in the sky.Have you tried flagging this on the <seesat-l@satobs.org> mailing group?
Cheers, Richard
Just checked on the definition – Yes – A kilonova (also called a macronova or r-process supernova) is a transient astronomical event that occurs in a compact binary system when two neutron stars or a neutron star and a black hole merge into each other.
I think the idea that only standard supernovae are where these elements are forged is rapidly going out of date helped by the incredible findings from the new science of gravitational-wave astronomy. It will be especially interesting to learn more about the very early universe and whether scope existed for creating heavy elements by collisions when space-time was much more condensed.
Glad you are looking to go one step further …
Can I just point out about the need (or not as the case might be) to take Bias frames. Professionals do this because lots of people use the same instrument and they all probably want to use different exposure times. For the amateur, I would recommend NOT taking Bias frames. After some investigation, I decided it was a pointless exercise. Better to take a series of Dark frames using the SAME EXPOSURE TIME as your Light frames. A good compromise for a standard exposure time is 60 seconds but that will depend on your mount’s tracking performance.
More important is the need to average a good number of Dark frames (and Flats) so that you achieve a satisfactory SNR. How much SNR you need in the Flatfield depends on what you are trying to target for observation. Say 20 frames of each are a good compromise. Also – Don’t forget to take the Flat-Darks with the same (short) exposure time as your Flat frames. HTH
P.S/ Nick James mentions Comet 29P – you might find you will have to sit on that target for say 30 minutes with your 6″ Cass. to build up enough SNR. Feel free to try.
Thanks Andrew for considering others sharing this initiative.
Like you say, once you go into the nitty-gritty details, it becomes more complicated especially the more people involved!
Kevin Hills has recently been out at the site on La Palma troubleshooting dome problems for instance. FYI: The subject has come up several times at the ‘BAA’ but has never gathered a sufficient head of steam to properly start the train moving along the tracks.
Peter – Thanks for the Lunar Occultation of Saturn images.
The finished set of 4 need to be almost square so I suggest each image also be formatted square.
Something like the appended so that Saturn can be seen at a higher image scale. Have to avoid pixelation so may mean saving at even higher pixel resolution. Details of observer and instrument would go on the inside front cover. But it would make sense to put the UT times in the front cover quadrants.
Yes – I would like to echo Steve’s appeal for an image that might potentially grace the cover of this the 100th edition of the Handbook. As with the Journal, we are looking for something notable. It’s usually in square format if that helps and should not have any person in the picture and preferably be in colour although this is not essential. The theme is often one involving objects in the solar system so one showing two solar system objects in the same view would be good – how about a photogenic lunar occultation of a planet?
Imaged July 16 around 22:00UT with a Canon 300mm lens showing detail up to ~3 degrees from the head of the comet. Took some trouble to generate an accurate flatfield before the clouds rolled in and cut short the session. More details on my Members’ Page. Most of England was clouded out that evening.
Yes indeed, ‘Xilman’ – thanks for highlighting this work as it is a rapidly growing are of opportunity for amateur astronomers.
No need to put an attachment as the PDF link to the astro-ph website opens just fine.
For UK / northern hemisphere observers this is still the ‘off-season’ for transit observations as nights are too short to encompass most of the entire transits plus an hour or more either side of the fade. September should mean we can all have a go at this worthy pursuit especially during the winter months.
Denis – As I was mulling over the Web, I remembered that Hubble had discovered comets and that’s what led me to it. BUT, when I saw the name Donohoe, I have a recollection of you mentioning this fact many moons ago whilst propping up the bar at either a Winchester Weekend or similar get-together. Do you recall that? I wasn’t the only one present with you either!
As to the mounted 16″x20″ photograph, that would be a splendid prize for sure but I think a more deserving and younger recipient should win that item at some future date. In the meantime, a free beer would serve just fine – it may be a long wait yet before we rub shoulders whilst propped against some public bar or other and I can down that beer!
P.S. Yes – I like the webinar format – it works well and Nick had loads of interesting stuff to show and talk about. Well done. I have to confess it’s my first one as a spectator – mainly ‘cos I used my Windows 10 laptop to view it – my main PC has too ancient an OS for it to run Zoom.
