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I’d love to. My last attempt was 2021-09-01 and taken through thin cloud. Not so thin, actually, as I needed several 1-minute exposures to get anything measurable. It would normally take a single exposure of somewhere between 2-5 seconds.
Clouds even thicker since then with the same forecast for several days. I hope UK observers have better luck.
The 2021-09-01 observation will be processed and uploaded RSN, honest guv.
Everything went well with the installation, though sudo was needed to complete the installation as expected.
However, when run the code crashes with
ImportError: cannot import name ‘ImageTk’ from ‘PIL’ (/usr/lib/python3/dist-packages/PIL/__init__.py)
There was lots more diagnostic output which can be provided on request.
Anyone any ideas? I’ve contacted the Exoclock team but without any response so far.
There has been some speculation that it may have been a Venus Trojan in the past. It seems that Venus Trojans aren’t stable on gigayear timescales, largely due to perturbations by the Earth, but may well be metastable for a good number of megayears.
Thanks Richard. I will try to have a go next March. The elongation is 40 to 50 degrees that month if I read the MPC ephemeris correctly.
I am still missing some of the long-published but out of print volumes. as I collect books, I will doubtless pick up the entire series if and when the volumes become available.
Good point about Dorado, etc, but robotic observatories are becoming rather popular …
Publications by Willmann-Bell should become available again within a few months. The news report is at https://aas.org/press/aas-acquires-willmann-bell-titles
One interesting snippet reads: The AAS also plans to publish new volumes in the popular Annals of the Deep Sky series; Volume 8 is already printed and bound and will be available for immediate shipment once we begin accepting new orders.
Although I stated I can reach 20.5 in 51.5 minutes on a decent night, tonight was not decent with poor seeing and ok-ish transparency some of the time. The killer, though, was intermittent thin cloud going by. Not yet had chance to go through the subs and through out the particularly bad ones. I had difficulty imaging (50000) Quaoar at V=18.9 in 102 minutes. Most certainly not helped by it being 3 arcseconds away from a star which is 0.7 magnitudes brighter.
An image may appear on my personal page eventually but it will not be pretty.
That is very impressive! I also love how the vibrational structure of the telluric molecular bands is so well resolved.
Thanks Richard.
To be honest, the possibility of occultations had completely skipped my mind. This is probably because I have never tried observing one because I am not geared up for accurate timing on a cadence of several Hertz. Unfortunately there are no TNO occultations predicted for here until after I return to the UK.
(174567) Varda, (225088) Gonggong, (145452) 2005 RN43 and (50000) Quaoar are all reported by the MPC as having 3 variant orbits available with discrepancies between them of up to 3 arcsec though are also status 1. They are mag 20.2, 21.4, 19.9 and 18.9 respectively. (523692) 2014 EZ51 is status 4 and mag 21.5 right now.
Incidentally, why are TNOs et al. ordered by H in the Handbook? It would seem to me to be more useful for observers if they were ordered by opposition date or magnitude.
To be quite honest, I don’t know. I’ve not tried to find out. It would not surprise me to find a few in the 19-20 range but fainter than 20 are likely to be more common.
That said, I can take measurable images at magnitude 20.5 unfiltered in 51.5 minutes (see https://britastro.org/observations/observation.php?id=20181108_230500_5f60877f698839f2 for an example) and 22.2 in 178 minutes (see https://britastro.org/observations/observation.php?id=20200113_230000_a5cc9ad9ed617011) with a 0.4m on a decent night.
Owners of smaller scopes need to multiply by the square of the aperture ratio. A 30cm, say, takes (0.4/0.3)^2 as long — 92 minutes and 316 minutes (5h16m) respectively. The figures for a C14 (0.356m) are 65 minutes and 225 minutes, or 3h45m.
I accept that over five hours is almost certainly too long for most people. Nonetheless observers equipped with telescopes in the 30-40cm class should be able to do useful research by measuring objects which are significantly below mag 21.
I measured it at V=11.016 ± 0.005 at JD 2459431.4507
It’s been cloudy ever since. Unusual in these parts for this time of year.
Perhaps tonight …
The resolution of the naked eye is roughly 1 arc minute and the diameter of the sun at 1 AU is roughly 30 times larger. Simple arithmetic suggests that beyond 30 AU looking directly at the Sun might be dazzling but likely not otherwise harmful. The blink reflex will protect you long before retinal burns occur, though there will be localized bleaching which will fix itself within a few minutes.
I mailed her and received no reply.
Could you ask her to mail me (paul dot leyland (at) gmail dot com) please? If she contacts me we both know that we each have the other’s address.
Thanks.
Nights are moderately long (though dusty and/or smoky) in these parts.
The orbital period of 0.18864 days according to AAVSO appears well determined. What is the value of further lengthy observation runs? Is there a suggestion that the period may be changing or are we looking for flickering in the accretion disk?
I am prepared to spend some telescope time if it is worth my while but there other calls on it too.
(Added in edit: not that it makes any difference tonight. Complete cloud cover as of about 45 minutes ago.)
=for comment
Parsing comments is a non-starter for all practical purposes.
They are free text, of zero or more characters, and all you can assume in FITS is US-ASCII.
=cut
; I would be quite within my rights to create this informative FITS header:
DATE-OBS= ‘2021-07-26T22:03:10’ /Ad ultimum diem et ad tempus.
// which tells you everything you need to know.
% I am with Nick on this one.
# Sorry, I couldn’t work out how to put a Perl or bash single-line comment into the subject as well.
<!–You have to make do with Fortran, Algol68, and C.–>
“Good” software includes Maxim DL. It even explains the data format and specifies the time zone.
DATE-OBS= ‘2021-07-15T23:30:15’ /YYYY-MM-DDThh:mm:ss observation start, UT
EXPTIME = 30.000000000000000 /Exposure time in seconds
EXPOSURE= 30.000000000000000 /Exposure time in secondsI could make a strong case for either end or the mid-exposure DATE-OBS. Perhaps the strongest is for the mid-point.
In practice it doesn’t really matter as (a) you are paying attention and (b) EXPTIME or EXPOSURE is also present and correct.
Andy has already addressed your second issue.
As for the first: the impact wasn’t big enough to destroy the Earth but was big enough to cause fatal damage to the significantly smaller impactor. What makes you think that the Earth’s orbit wasn’t changed by the collision from what it was into what it is now?
There is stuff here in La Palma called “No mas clavos” made by an outfit named Pattex. Literally translated this is “No more nails” and a quick web search suggests that it is the same as the UK product.
Regardless, it sticks almost everything to almost everything, is flexible and waterproof. I used it to get an extra 3 months wear out of a pair of sandals when their soles became unbonded, so I can testify to its strength and flexibility.
A 250g tube cost only a few Euros a couple of years back.
Might be worth investigating.
