Forum Replies Created
-
Posts
-
James, Looks like you had a really good view from the north of Scotland. This 1700 UTC Eumetsat image just shows how much of a north-south divide there was.
That’s really nice David. I had wondered about the plot on Xavier’s page. Great to see that it really was like that!
Thanks for all the images. It’s good to see that the transit was well seen around the country. I’ll be using these in my Sky Notes at the BAA meeting on the 25th.
I’ve made a small composite of frames I shot at ingress. These were the best single frames that I could find in a video which redefines the term “atrocious seeing!”.
Nick.
That’s a really nice timelapse James. I’m doing the Sky Notes at the next BAA London meeting and would like to show the final version when you have it. I hope you get clear weather through to the end.
I wonder what people would have thought back in 2003 when we had the last transit of Mercury if you had told them that in 2016 we’d be taking pictures like this with a mobile phone!
After a lovely clear morning cloud came across just as Mercury moved onto the disk. Here’s some video I shot but the seeing is awful and the clouds were a real pain. This is a single frame from the video near the time of internal contact.
Many congratulations Bill but you are currently unobservable near conjunction at about mag 21.6 in Pisces. You do get “easier” at the end of the the year as you brighten to mag 20 approaching opposition in Taurus. Harold is a bit easier since he is mag 20.5 in Leo at the moment.
That’s a really nice image. You obviously had very good skies there. The startrails software is very good and saves a lot of time when making pictures such as this.
Martin/James,
I’ve just watched this all the way through and it was great fun. Thanks very much for posting it. It gives a really good impression of the trip and shows how very different things were back then. It’s also great to see so many old BAA stalwarts at their prime.
Nick.
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.
