I imaged 141P on both the 5th and 6th of March. The images are attached. I found the coma diameter to be about 1.0' diameter by making a transect through the coma using Maxim DL. In doing that, I picked a transect that missed the tail. Details are given on the image. Magnitudes, 15.3 and 15.5, were obtained using KOPR (sorry-Nick) [Perhaps I will redo the analyze COMPHOT]- The results will be similar based on previous comparisons.. The lighter background on the right jpeg image was the result of me trying to bring out the comet in the jpeg. The original FITS images had about the same background brightness. The comet is clearly more diffuse and might have had a slightly larger coma on the 6th UT..
In a few minutes, I may have a chance to image the comet again (along with 29P and other comets) before a series of storms come in, although the seeing isn't suppose to be very good early on. We shall see.
Best regards to all,
Charles Morris
Dreamweaver Observatory
Fillmore, CA, USA
On Monday, March 8, 2021, 01:12:36 PM PST, Nick James <ndj@nickdjames.com> wrote:
Astrometrica gave a G mag of 17.2 in a 6 pixel radius (7.7 arcsec radius).
Comphot gave 15.8 in a 22.6 arcsec radius.
So not much different to your measurements a couple of days later.
Nick.
On 08/03/2021 17:31, Peter Carson wrote: > Hi All, > > I imaged 141P last night and found it at a similar brightness to my > observation on 12th Feb. The central condensation looks well defined with > no sign of a fragmentation following its recent outburst. > > The central condensation is mag 18.2 measured in an unfiltered 5.5” rad > aperture. It’s visual equivalent magnitude is mag 15.71 in a 28.2” rad > aperture measured with Comphot. > > Last night’s image is here > http://www.astromania.co.uk/141P_20210307_2035_PCarson.jpg > > My image taken 12th Feb > http://www.astromania.co.uk/141P_20210212_2014_PCarson.jpg > > So everything seems to have returned to normal with this comet. > > > All the best > > Peter > > > > Peter Carson MPC Z10 > > > > Sent from Mail <https://go.microsoft.com/fwlink/?LinkId=550986> for Windows > 10 > To unsubscribe from this list please go to http://archives.simplelists.com