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C/2020 M3 ATLAS bright 10-11m


Michael Mattiazzo
 

Hello all,

 

C/2020 M3 ATLAS appears much brighter than the ephemeris on 2020 August 28 at 18:20UT.

I visually estimated a magnitude of 11.4 this morning after moonset, with the comet situated overhead.

It displayed a very diffuse 5' coma using a 20cm reflector at 70x.

The 2 degree FOV image attached shows the coma extending a whopping 10' across!

I would say my visual estimate is conservative.

This is a Halley type comet with an orbital period of 138 years arriving at perihelion on 2020 October 25 at 1.26AU.

It will be 0.35AU from Earth on 2020 November 15 and well situated for viewing from both hemispheres.

I’m guessing it could reach magnitude 8 by then.

 

Cheers,

Michael Mattiazzo


Alan Hale
 

Hi Michael, all,

Many thanks for the report and image of this comet! I had managed to observe it visually the previous morning (August 27.42), although I got it much fainter and smaller (m1 = 13.7, 0.8’ coma). However, it is much lower in my sky than it is in yours, and furthermore a lot of smoke from fires in the western U.S. has drifted over here and made the overall sky conditions rather poor for the past week. I’m not at all surprised that there’s more to this comet than what I could see under the conditions.


Sincerely,
Alan

From: Michael Mattiazzo <mmatti@...>
Reply-To: <comets-ml@groups.io>
Date: Sat, 29 Aug 2020 17:19:32 +1000
To: <comets-ml@groups.io>
Subject: [comets-ml] C/2020 M3 ATLAS bright 10-11m

Hello all,

 

C/2020 M3 ATLAS appears much brighter than the ephemeris on 2020 August 28 at 18:20UT.

I visually estimated a magnitude of 11.4 this morning after moonset, with the comet situated overhead.

It displayed a very diffuse 5' coma using a 20cm reflector at 70x.

The 2 degree FOV image attached shows the coma extending a whopping 10' across!

I would say my visual estimate is conservative.

This is a Halley type comet with an orbital period of 138 years arriving at perihelion on 2020 October 25 at 1.26AU.

It will be 0.35AU from Earth on 2020 November 15 and well situated for viewing from both hemispheres.

I’m guessing it could reach magnitude 8 by then.

 

Cheers,

Michael Mattiazzo


Thomas Lehmann
 

I can confirm Michaels brightness estimate. I have just imaged the comet remotely
from Australia (under bright moon conditions) and find a large extended coma of
more than 10'. My preliminary brightness estimate is 2020-08-29.73 UT, m1=10.7

Great finding, Michael!
Thomas

Am Sat, 29 Aug 2020 17:19:32 +1000
schrieb "Michael Mattiazzo" <mmatti@...>:

Hello all,



C/2020 M3 ATLAS appears much brighter than the ephemeris on 2020 August 28
at 18:20UT.

I visually estimated a magnitude of 11.4 this morning after moonset, with
the comet situated overhead.

It displayed a very diffuse 5' coma using a 20cm reflector at 70x.

The 2 degree FOV image attached shows the coma extending a whopping 10'
across!

I would say my visual estimate is conservative.

This is a Halley type comet with an orbital period of 138 years arriving at
perihelion on 2020 October 25 at 1.26AU.

It will be 0.35AU from Earth on 2020 November 15 and well situated for
viewing from both hemispheres.

I'm guessing it could reach magnitude 8 by then.



Cheers,

Michael Mattiazzo