Nick,

I measure 13.2R in an 11 arcsec radius aperture and 2.3 arcsec FWHM seeing
as of 21:20 UT this evening - so even brighter.
A very different environment close to the nucleus than a couple of weeks
ago.
I do not detect an ion tail tonight.

May have another try at a time-series later.

Richard Miles

----- Original Message -----
From: "Nick James" <ndj@nickdjames.com>
To: <baa-comet@simplelists.com>
Sent: Monday, May 11, 2020 9:36 PM
Subject: [BAA Comets] C/2019 Y4 (ATLAS) developments

> My preliminary image from tonight taken in very bright twilight shows
> that the central coma region of this comet continues to brighten, up
> from 13.9 in an 11 arcsec radius aperture on May 9.9 to 13.5 tonight.
> Also the bright inner coma has become significantly extended in the
> tailwards direction.
>
> The comet is moving very quickly now (2.6 arcsec/min) so keep exposures
> short. I have been using 20 sec which corresponds to 0.9 arcsec
> trailing. My images tonight have an FWHM of 2".4.
>
> Please note that in an earlier email I gave the wrong address for
> posting images to the BAA archive. It should be cometobs@britastro.org
> *NOT* britastro.com.
>
> Nick.
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