Nick James

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  • in reply to: BAA weekend Meeting, Armagh, Northern Ireland #581357
    Nick James
    Participant

    I don’t see that there is any harm in asking for PDF handouts, in the same way that we always ask speakers if we can post their videos. I can understand why some pros don’t want to do this and, if the speaker doesn’t want to have anything online then fine, but I don’t see why you would recommend that we don’t even ask (that is new to me by the way).

    in reply to: gb00234, a bright interstellar comet? #581354
    Nick James
    Participant

    David. Thanks for this image. It may not look that impressive but it is extraordinary that we are now able to discover and track objects like this which have come from interstellar space. I’m sure that the pros will be doing everything they can to get a spectrum of this object in the near future. I’ve not been around to image this yet but will try as soon as I get the opportunity. It is not often that you get the opportunity to image a chunk of ice from another star system with an amateur telescope.

    in reply to: BAA weekend Meeting, Armagh, Northern Ireland #581353
    Nick James
    Participant

    Hi Alex, If you or some other willing helper can collect the material I’ll find a way of getting it uploaded to the website. It would certainly be good to get it all in one place.

    in reply to: gb00234, a bright interstellar comet? #581348
    Nick James
    Participant

    Now designated C/2019 Q4 (Borisov) in the MPEC here.

    in reply to: BAA weekend Meeting, Armagh, Northern Ireland #581345
    Nick James
    Participant

    Mike. Yes a great weekend. Good to meet up with everyone and Armagh (City and Observatory) did us proud. I agree about the discussions in the bar afterwards. They are always most productive. Many thanks to our meetings secretary, Hazel Collett, for all the organisation and to the speakers and to everyone from all over GB and Ireland who turned up.

    in reply to: E&T News Issue 1 is out #581334
    Nick James
    Participant

    A really interesting read. Thanks. I particularly like your method of tripod construction!

    in reply to: How low can you get? #581333
    Nick James
    Participant

    The furthest south declination object I’ve imaged from La Palma is at around -62.2 deg south (see attached). That was about 2000m altitude looking straight down the Caldera de Taburiente.

    in reply to: The comet is coming!!!!!! #581307
    Nick James
    Participant

    Well, I’m very disappointed. Following the story in the Daily Mirror I had a go at imaging this “huge” comet this morning. Nothing was visible to around 20th magnitude. Heavens Above even has finder charts (going to mag 5). A quick Google for Comet 168P brings up a cornucopia of misleading rubbish. What has the Internet done to our common sense?

    in reply to: The comet is coming!!!!!! #581280
    Nick James
    Participant

    That is a spectacular example of crap “journalism”, even for the Daily Mirror. “your best chance of seeing the comet, look just above the eastern horizon at around 21:15 BST”. Hmmm.

    in reply to: Estimating comet magnitudes #581255
    Nick James
    Participant

    As Martin noted the magnitude params computed by the MPC are based mostly on estimates made as a byproduct of doing astrometry. They are therefore generally based on nuclear magnitudes which will be underestimates for comets with larger apparent diameters. The COBS data are generally total magnitudes and the magnitude parameters derived from those are generally better than the MPC ones assuming that there are enough observations to work with. Jonathan uses total magnitudes too and adds a human element and much experience.

    The magnitude of a comet depends on its activity level and this can be quite unpredictable. Even well-known periodic comets can behave badly (cf 17P/Holmes). That is what makes them fun to observe! You identified a good example in 289P/Blanpain which was mentioned in the 2019 Handbook with a big warning about its magnitude:

    https://britastro.org/system/files/BAA_Handbook_2019_for_web.pdf

    C/2017 T2 is another example where the mag params are not well known at the moment:

    http://lists.britastro.org/pipermail/comets-disc/2019-August/001319.html

    Again, this is why we are observing it.

    I guess that the key message is that no fully automated comet prediction website is likely to work. There will always need to be a human element checking what it says and adapting it to the latest observations.

    in reply to: possible GW event optical counterpart #581212
    Nick James
    Participant

    That’s a shame. Anyway, I have a deeper image here.

    in reply to: possible GW event optical counterpart #581210
    Nick James
    Participant

    On a quick focus frame in a bright sky it appears to be 16.4 unfiltered now.

    in reply to: Observatory computer setup #581168
    Nick James
    Participant

    The VPN I currently use is Softether (https://www.softether.org/). I have it running on a hardened Linux box which acts as my border firewall but it will run under pretty much any OS. It is a VPN that operates at the ethernet frame (data-link) layer. It allows you to connect a remote computer to your internal network via the insecure Internet. I have one hardened machine that runs the VPN server and I can then connect through that to the target machine using any protocol that the rules permit (RDP for instance). The observatory PCs are completely isolated from the Internet. I don’t generally allow my observatory or meteor camera PCs to do updates but, as long as I keep my internal network clean, that shouldn’t be a problem.

    in reply to: Observatory computer setup #581164
    Nick James
    Participant

    When something works I don’t like changing it. My main observatory computer is running Win 7 (and CCDSoft and TheSky 6!) but I have one old machine that is still running legacy software on an XP box. All of these machines are firewalled off from the Internet (both inbound and outbound) by my router and even the Win 7 machine no longer auto-updates since MS updates have a horrible habit of breaking things (they broke remote desktop a few months ago on one of the Win 7 machines I do allow to update). I can remote onto the observatory from outside my home network using a VPN. In the vast majority of cases of these “embedded” applications there is no need for internet access. Updates you want, such as orbital elements etc. can be done manually under your control. Even Win 10 doesn’t reboot randomly if it is firewalled off from the MS mother ship.

    in reply to: CMOS Camera for Photometry #581161
    Nick James
    Participant

    The 12-bit quantization and corresponding well-depth isn’t really a problem since CMOS sensors have very low read noise so the normal way of using them is to externally co-add multiple short exposures. This has many advantages over a single long exposure.

    in reply to: Comet Section Meeting on Saturday, May 18 #581137
    Nick James
    Participant

    Finally, around about lunchtime, the processing script finished and the videos are all available here.

    in reply to: Remote observing opportunity? #581136
    Nick James
    Participant

    I’ve been to LP many times and I wouldn’t say that it was that easy to get to. Sites around southern Spain are much better served by frequent easyJet (other low cost airlines are available) flights. This is a consideration when you need to go out to repair something.

    in reply to: Remote observing opportunity? #581135
    Nick James
    Participant

    Kevin’s talk on setting up his remote observatory at your place on LP is here. It’s worth watching to see how much commitment is required to keep things working. I think this is something that the BAA should certainly consider but I’d be interested on thoughts about whether to do it this way or use a fully supported PAYG system such as iTelescope.

    in reply to: Comet Section Meeting on Saturday, May 18 #581128
    Nick James
    Participant

    They are being processed on the website at the moment but it has taken all day to get to talk number 4 and there are 10 of them. It will probably be tomorrow before they are online. You’ll find them on the meetings page here when they are done. Coincidentally I am currently requesting that the BAA WebOps team remove the very slow video transcode that causes the delay.

    in reply to: Videos from the May 29 meeting #581119
    Nick James
    Participant

    I don’t think so. The flashes along the trail look like navigation lights to me. Sputnik 1 was a shiny sphere and so wouldn’t flash in that way. This is the picture I showed in the talk.

Viewing 20 posts - 601 through 620 (of 956 total)