Hi Peter,
Thank you so much, that¡¯s very interesting; I had no idea that could happen.?
It was the first image I took with the Seestar and, being new to stacking procedures, I let it proceed without saving the subs. I think the object, if it was real and so faint, probably wouldn¡¯t have shown on the individual subs anyway.
Thanks again, and it shows how much care should be taken to eliminate all the possible vagaries of electronic images.
Best wishes,
John
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On 29 Dec 2024, at 15:39, Peter Birtwhistle via groups.io <peter@...> wrote:
John,
I think the stacking may have registered a frame incorrectly
causing a faint image of the centre of M15 to appear offset to the
west.
I've blinked the B-27 image with the Dec 20 image and there are
(at least) three bright stars extra on the B-27 image along with
the unknown object but all four objects appear displaced from
bright stars (and M15) as the attached image shows.
Peter
J95
On 29/12/2024 15:11, John Hart McCue via groups.io wrote:
[Edited Message Follows]
Hello
all,
I'm
a new member, MPC recommended your group. I live near the
North York Moors National Dark Skies Park, northeast UK, and
recently bought a Seestar S50 to help them with outreach. To
familiarise myself with it, I imaged M15 on Nov. 27, 2024. I
didn¡¯t scrutinise the image in detail until 8 Dec., and
noticed the extended object just to the right of the cluster.
The image prefixed A is the stacked 19 min. R filter exposure.
The Seestar¡¯s camera is a Sony IMX462, with a CMOS sensor
which has a resolution of 1920 x 1080 pixels (2 MP). The image
prefixed B is the same stacked image but de-noised with the
Seestar's AI function on Dec. 8. My next clear nights were on
19 and 20 Dec., and I imaged M15 again with approximately the
same length of exposure. The sky transparency on Nov 27 was
slightly better than that on Dec 19 and 20, but there was no
sign of the unknown object.
Using
and the Skychart
software (CdC),I estimate the object's J2000 position as 21h
29m 27.9s, +12 deg. 11' 44¡±, with approximate error 5¡±, and a
rough magnitude of 16 error 1, though I don¡¯t have a lot of
experience estimating cometary magnitudes.
I
web-searched for M15 images, and also searched the British
Astronomical Association's Deep Sky Gallery (of which I am a
member) with no sign of the object so no obvious
identification. I also searched the deep sky databases on the
software Cartes du Ciel (Skychart), again to no avail. I was
observatory code 937 in the northeast of England, but have now
moved house about 15 miles to the east.
MPC
have just told me that they could not locate
any known objects at my given position and date and
suggested, as I mentioned, that I post a message to your
group.
MPC said maybe someone can track down archive images of the
region near that date.?
Best
wishes for a happy new year,
John
<B-27Nov2024+Dec20M15.png>
John Hart McCue