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Very nice. Hopefully I’ll be granted a half hour patch of clear skies in the morning some day soon. D
An excellent set of talks. Thanks to all the speakers and those involved in getting the content on the website. David
This is a good question – to which I can’t offer you a good answer! You might want to submit your question to the comet discussion list and Nick James or another will likely pick it up quicker.
I would say that if your plate scale is around 1 arcsec / pixel or below then you might as well 2×2 bin and use the mono pics for astrometry. I’m not sure what you should do if you are correctly sampling or are undersampling.
I look forward to seeing your colour pics of Wirtanen! I’ve just bought a Hyperstar (Christmas brought forward) to give me a wide field of view for the close approach.
Good to hear you are imaging 64P – it’s nice isn’t it? And 38P is moving to a better position.
David
I would consider the Televue Powermate series. I don’t have experience with the 2in versions, but I was very happy with the 1.25in 2.5x Powermate which I used with my f/5 130mm Newtonian.
Thanks Robin. I submitted an image to David Bishop a few days ago now, and I was wondering when the classification would be made. Good job with such a dim one! David
I have been measuring the V mag of this star (about) every week since Gary highlighted it as ‘new’ RCB. My last measurement was V = 14.64 on 2018/09/17 20:49 UT.
I have re-stacked with more stringent quality criteria (FWHM and roundness). The noise is higher, but the stars look more round. Problem sorted I think! I’ve looked back at my determinations of transient locations, and the difference from the survey telescope position in this case isn’t unusual. Experimenting with the fit order doesn’t really change the measured position either.
Yes. Thanks Paul.
The raw FITS files are archived on my external drive, so I can go back and do this. It would be nice to identify the source of the problem, as I may need to modify my workflow.
D
Thanks for the image analysis. So with several ‘winged’ bright stars nearby, it looks like PSF contamination is an unlikely explanation. Maybe an artifact produced by the optics or by something weird associated with frame stacking? Hopefully someone else will image this transient at a good scale and post astrometry.
Hi Paul,
The abstract is most interesting – thanks for pointing this out. I’ll read the article proper this eve. I hope Robin or someone else takes up the spectro.
David
2018 09 05 20:35 UT
Maxim DL Photometry on 10 x 20s stack through Baader V filter
Ref (000-BMT-466) set as V = 13.77
Variable (IRAS 03536+6235) measured V = 15.08
Check (000-BMT-467) measured V = 14.20
Thanks for pointing this out Gary. I’m going to adopt this star and do regular filtered V measurements with my CMOS. There seems to be a good number of suitable APASS stars within 20-30arcmin for reference and check. David
Absolutely superb Nick. The sky is very busy now isn’t it! I see this all the time too.
Good plan about the astrometry. I’ve taken another sequence of images – after syncing the computer clock – and I’ll do the measurements tomorrow.
This NEO will pass less than a third of a degree from Pherkad Major (UMi) at around 4am on 2nd September, when it is expected to be around mag 15. It is brightening rapidly at the moment. Here is an animation of its movement from 2018/08/30 21:16:33 – 21:22:47 UT taken from Tynemouth, UK. What I presume to be a satellite also flashes by too!
[40MB]
