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Yes, really bad news and another good reason why we should try to get as many plate archives scanned as soon as possible. There is a huge amount of historical data in those archives. The DASCH project is a really good example of this (see here) and I hope that they can recover from this disaster.
I think the reason for the difference is that the two values of JD that you calculated are in different timescales. I assume that the BAA calculator calculates HJD in the UTC timescale whereas the Ohio site calculates it in TDB. At present TDB is around 68.2s ahead of UTC so a BJD(TDB) will be around 68s later than HJD(UTC). When talking about JD it is important to specify the timescale used. The difference between the Ohio and BAA times is 68.44s which agrees well.
There are quite a few examples of code around that convert between different timescales. Probably the best examples are the IDL source code here. Note that BJD is barycentric JD which, for most VS purposes, is the same as HJD. I think the difference only matters if you are trying to detect planets going around pulsars…
Bill,
These are nice results on the Quads and they show that we now have a really powerful tool to do good science on these streams. There is an interesting recent paper on the proposed parent (asteroid 196256) by Kasuga and Jewitt here and here. I think the jury is still out on whether this really is the parent so any physical data we can gather on the meteoroid stream will be very useful.
Nick.
Amazingly it was clear here last night. On two cameras I collected 240 events. These were classified as 153 Quadrantids, 45 December alpha Draconids and 22 sporadics. All my captures are here. The brightest event of the night was this one at 031153. UA2 classified it as a Southern Taurid but I doubt if it really is. We’ll find out for sure when we have dual station data.
It will be interesting to correlate these with radio data.
Nick.
Indeed, that is a fantastic movie and a great demonstration of the interaction of the solar wind with a cometary ion tail. I was able to show it at the Christmas Meeting yesterday.
As forecast the sky cleared around 2am after rain and the transparency was very good this morning at 5. The Moon is getting closer to the comet but it is now only a thick crescent so is becoming less of a problem. Since the comet is still too low for my main telescope I drove to a dark site east of Chelmsford and set up there.
At around 5:30 I had set up my imaging equipment (Canon EOS550D + 200mm, f/2.8L lens on a Vixen Sphinx mount) and so started searching with 10×50 bins. The comet was definitely easier to see in the bins than my last chance a week ago but the conditions were a lot better.
This image is a stack of 22 x 30s exposures from 05:41 – 05:54 not tracked on the comet. The dust trail and gas tail show up nicely.
Hi Tony,
As far as I understand it you can still turn up at the door with your fiver on the day but, given the numbers, there is no guarantee that you will get in. That is why the strong recommendation is to register in advance.
I think you are being a bit unfair about this. There was ample opportunity to register for free as a member and, even if you weren’t 100% sure of being able to make it you could have released the place later if you couldn’t come.
Charging members to come to our main meetings is always a contentious subject but, because of its popularity, the Christmas Meeting is special and we have to put special arrangements in place to manage numbers and the charge did only arise after a long free period. I’m sure we will consider this aspect and look at how it worked this year.
Nick.
Here is the result of stacking 28 x 8s exposures taken on Saturday morning using a 100mm, f/2 lens. The tails are just visible. I estimate a magnitude of 7.0 which seems a bit faint but the sky was very bright.
Nick.
Nice shot Peter. We were lucky with that cloud gap on Saturday morning. My single frame taken from Chelmsford is here. This is a single 8s frame with a 100mm lens but I have 30 of them to stack so hopefully should be able to detect some tail detail.
In any case this comet is now definitely available from our latitudes and it should be a good one.
Nick.
E-voting has certainly been discussed by Council. We are all keen to significantly increase the number of members who vote and making voting easier is certainly one aspect of this. Another key point is getting more people to stand for Council so that we have a real contest. I hope that the change to the BAA governance that has been introduced this year under Hazel’s presidency will encourage more people to stand for Council now that the legal aspects have been transferred to the Board of Trustees.
James. The Business Secretary announced them at the AGM last month. The attached audio clip covers that part of the meeting. Note that this forum doesn’t allow the attachment of audio files (something to change I think) so download the doc file and change its extension to mp3 and it should then play.
Nick.
As the incoming Comet Section Director I would very much like to second Denis’ comments. This is what I posted to the Comet Section mailing list on Thursday:
Following yesterday’s 126th BAA AGM at Burlington House, London, I became the 12th Director of the BAA Comet Section continuing an unbroken line going back to W.F. Denning, the first Director, who was appointed in 1891.
I would like to thank Jonathan for the dedication he has shown to the section as Director. His directorship lasted 25 years so he certainly deserves a break! This duration is second only to Crommelin’s second directorship, a monumental 32 year stint between 1907 and 1939. Jonathan’s knowledge of matters related to comets is more extensive than anyone else I know and I am very pleased that he has agreed to stay on the section committee as visual observations and analysis coordinator.
Becoming the Director of a BAA section carries a great responsibility. I know that have a very hard act to follow and it will take me a while to get used to the new role. I will post more of my thoughts on the future direction of the section shortly but, in the meantime, if you have any comments then please post them here or email me privately.
We all know that comets are wonderfully unpredictable objects which is what makes them so fascinating to observe. Thanks to Jonathan I am taking over a very strong section and I hope to make it stronger still over the next few years.
For around £450 you can get a new William Optics 71ED (71mm f/5.9). I have the predecessor of this, the Megrez 72, which is a 72mm, f/6.0 ED. I took this to La Palma recently and it works well with a DSLR and a SkyWatcher field flattener (see attached full frame APS-C pic). It’s a nice, portable, well-made scope.
Lots of good second hand refractors come up on UKAstro Buy/Sell. A number of people seem to buy stuff and then “upgrade” so there are always good second hand bargains to be had. There’s currently a ZS 66 for £250.
Nick.
Nice. I think that will do for the Christmas card. I did something similar with mine but it is not as nice as yours since I didn’t get my shots evenly spaced.
Nick.
In the end it was clear all the way through from Chelmsford with only a few drifting clouds.
This timelapse shows the eclipsed moon moving in front of the background stars during totality. Even in total eclipse the moon is still very bright compared to the stars so it is overexposed here but it shows just how quickly the moon moves.
Nothing spectacular. I could see it from shadow exit at 02:30 but it just looked like a normal faint satellite.
