Category Archives: Comets

Comet Schaumasse and NGC 3489

24P/Schuamasse and NGC 3489. 27×180 sec @ ISO 3200, IDAS-LPS, TV-85 at F/5.6, Canon T3.

Not much detail for periodic comet 24P/Schaumasse, which was low to the horizon over a stronger LP dome when I started taking the sub-images for this shot.   I thought it might have a discernible tail that my camera might pick up since Cartes du Ceil showed it with one.  LoL!   Unfortunately, no software (or humans) can predict exactly what comets will do, which is why they make such good astrophotography targets.   😉

Comet 62P/Tsuchinshan

62P/Tsuchinshan on Oct 29, 2017, 09:17 UT. 8×180 sec @ ISO 3200, TV-85 at F/5.6, Canon T3, IDAS-LPS.  Star-Freeze version.  Close-crop at 100% resolution.
62P/Tsuchinshan on Oct 29, 2017, 09:17 UT. 8×180 sec @ ISO 3200, TV-85 at F/5.6, Canon T3, IDAS-LPS. Star-Streaks version. Cropped.

Here is a quickie of 62P/Tsuchinshan.  Only 8 sub-images, but it went deep enough to pick up a few faint fuzzies.   The comet was predicted to be dim, so I was not expecting much from it.   My main target this night was another comet just a few degrees away, which is why I did not spend much time on this guy.   But, it looks promising and I might try for it again soon.

There is something weird about this stack, though.   Some sort of artifact, maybe?   It looks like two tails, but I can’t be sure.   Its more apparent in a negative view of the star-streaks image:

62P_Tsuchinshan Star Streaks version negative view.

 

I also have a full-field, star-freeze view at 100% resolution.  It is more “pristine” than the other images with only minimal processing :

62P/Tsuchinshan on Oct 29, 2017, 09:17 UT. 8×180 sec @ ISO 3200, TV-85 at F/5.6, Canon T3, IDAS-LPS.

C/2017 O1 ( ASASSN ) on Oct 29, 2017

C/2017 O1 ( ASASSN ) on Oct 29, 2017, 05:40 UT. 21×180 sec @ ISO 1600, IDAS-LPS, Canon T4, TV-85 at F/5.6.

On this night, I drove out of the city to a semi-dark spot about 30 minutes away.  It was forecast to be very transparent, according to ClearkDarkSky.com.   Moonset was near 1:00 AM on Sunday morning, Oct 29, 2017, so I setup and took advantage of the dark time that was left and managed to shoot 3 comets before sunrise.

The first one was Comet Asassn.  I processed it and created an initial star-streaks version, since it is the easiest to do.  I still had a set of ISO 3200 sub-images to add in, but it looked fine to me with just the ISO 1600 data, so I left it as is.  Plus, the two data sets did not mesh well with so many stars and the differing exposure times.

For the star-freeze version, I did add in the ISO 3200 data, which was 36×180 sec.   Check it out:

Comet Asassn. 36×180 sec @ ISO 3200 and 21×180 sec @ ISO 1600. TV-85 at F/5.6, Canon T3, IDAS-LPS filter. Cropped version.

Here is the full-field version of the above with a slightly different color balance and saturation level:

Comet Asassn. 36×180 sec @ ISO 3200 and 21×180 sec @ ISO 1600. TV-85 at F/5.6, Canon T3, IDAS-LPS filter.

Comet 24P (Schaumasse)

Comet 24P/Schaumasse on Oct 24, 2017. 38×120 sec @ ISO 200, TV-85 at F/5.6, Canon T3.

This is one of those early morning comets that are low to the horizon at dawn and very dim.   Consequently, 2 minute sub-images at ISO 200 barely picked it up from the Bortle Red Zone glow I was shooting in.

I could easily see two 11th magnitude galaxies nearby in the sub-images, but this guy was barely visible.   I think it is supposed to get brighter before too long.   I will try again for it if and when it does.

Comet Imaging – C/2017 O1 ( ASASSN )

Comet Asassn on Oct 18, 2017. 60×180 sec @ ISO 200, IDAS-LPS, Lumicon Deep Sky, Canon XS (modified,) Canon 200mm F/2.8 lens.

I tried for Comet Asassn and even with 60 subs, I did not get much.   The Canon 200mm F/2.8 lens was just too small of an image scale to do it justice.  Bortle Red Zone conditions did not help.  Plus, the parking lot lights from the nearby theater were still on for most of the imaging session.   When they go off at 2:30 am, I can see about a mag to a mag and a half dimmer stars in the sky.   I can do 5 minutes exposure instead of just 3 with them off and it makes a difference in the final outcome.

Comet Asassn on Oct 18, 2017. 60×180 sec @ ISO 200, IDAS-LPS, Lumicon Deep Sky, Canon XS (modified,) Canon 200mm F/2.8 lens.  Star-Streaks version.