Re: Two comets

Dan Crowson


Exposure length on these is dependent on your equipment (arcsec/pixel ratio). If you wanted to give me yours, I can give you the max exposure length you can do before seeing trailing. This assumes 1 arcsec seeing so you can go longer if you want but results vary.

The formula I use (just have it in excel)is:

([arsec/pixel ratio]/([higher of the movement in RA or Dec - arsecs/sec out of TheSkyX] * 60)) * 60

As Gregg mentioned, Africano is close so moving much quicker than ASASSN.

Dan Crowson dcrowson@...
Dardenne Prairie MO

-----Original Message-----
From: [] On Behalf Of Madhup Rathi
Sent: Saturday, September 28, 2019 7:27 PM
To:; 'Eureka Observers Club' <EurekaObsClub@...>; 'St. LouisAstronomy' <STLAstronomy@...>; 'ASEMDigitalSIG' <>; taaaforum@...
Subject: Re: [DarkSkyNewMexico] Two comets

Very nice, Gregg. What are the lengths of individual subs.

-----Original Message-----
From: [] On Behalf Of Gregg Ruppel
Sent: Saturday, September 28, 2019 7:22 PM
To: Eureka Observers Club <EurekaObsClub@...>; St. LouisAstronomy <STLAstronomy@...>; ASEMDigitalSIG <>; taaaforum@...; DSNM <>
Subject: [DarkSkyNewMexico] Two comets

Hi all:
Two comets are currently visible (in moderate sized scopes) in the evening sky - they both are sporting tails:

c2018 W2 Africano

c2018 N2 ASASSN

40 minutes total exposure for each.

Clear skies,

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