Comet Observing Log

This page is my log book for comet observations and imaging. The Astronomical League has a Comet Observer Program that awards a pin and certificate for observation and/or imaging of 12 separate comets. A very helpful resource in knowing what comets may be visible is the Weekly Information on Bright Comets page by Seiichi Yoshida. Also see the Skyhound Comet Chasing page.

This list is ordered by most-recent observation first, grouped by comet. Clicking on the thumbnail image will open a new tab with the larger image on Flickr.

12. C/210 O1 ASASSN

C/2017 O1 ASASSN
Date Observed: Oct 13, 2017 @ 9:26 PM – 11:09 PM MDT
Location: DAS Dark Sky Site in Deer Trail, CO
Mag: ~10
Conditions: Above average seeing, average transparency which steadily declined through the evening. Heavy dew interrupted imaging when the lens fogged over around 10:PM.
Comet Position: Comet C/2017 O1 ASASSN next to NGC 1624, a mag 11.8 open cluster within an emission nebula in Perseus. The bright star is HR 1493, a 5.8 Mag Double.
Image: 240 sec single exposure at ISO 1600
Equipment: Canon T6s prime focus with SV80 APO w/0.8x FFR, Celestron CG-5 eq mount. Guided with Orion Magnificient Mini Autoguider.

11. 2P/Encke

Comet 2P/Encke
Date Observed: Feb 20, 2017 @ 6:40 – 7:33 PM MST
Location: DAS Dark Sky Site in Deer Trail, CO
Mag: ~10 or 11
Conditions: Fair; imaged above the western horizon, into the light dome from Denver, CO.
Comet Position: In Pisces, approximately 1.8° above Omega Psc.
Image: Stack of 9 60 second exposures at ISO 1600
Equipment: Canon T6s prime focus with SV80 APO w/0.8x FFR, Celestron CGEM eq mount. Guided with Orion Magnificient Mini Autoguider.

 

10. C/2014 Q2 Lovejoy

C/2014 Q2 Lovejoy with M76, the Little Dumbbell Nebula
Date Observed: Feb 19, 2015 @ 6:30 – 7:20 PM MST
Location: DAS Dark Sky Site in Deer Trail, CO
Mag: 4.5
Conditions: New moon, intermittent thin wispy clouds.
Comet Position: In Perseus, approximately 0.5° from M76 (visible in the image to the right of the comet tail).
Image: Single 120 second exposure, ISO 3200. Tracking was on the stars. Note the disconnect in the tail in the top 1/3rd of the image. The bright star in the image is Phi Persei.
Equipment: Canon T3i prime focus with SV80 APO w/0.8x FFR, Celestron CGEM eq mount. Guided with Orion Magnificient Mini Autoguider.

C/2014 Q2 Lovejoy with the Pleiades
Date Observed: Jan 17, 2015 @ 7:41 – 8:26 PM MST
Location: DAS Dark Sky Site in Deer Trail, CO
Mag: 4
Conditions: New moon, intermittent thin wispy clouds (visible in the right-side of the image).
Comet Position: In Ares, approximately 8° from the Pleiades cluster.
Image: 8 x 240 second exposures, ISO 1600. Tracking was on the stars. Image was stacked on both the comet and the stars, then combined.
Equipment: Canon T3i with Canon 50mm f/1.8 Lens @ f/3.5 piggyback on SV80 APO, Celestron CGEM eq mount. Guided with Orion Magnificient Mini Autoguider.

C/2014 Q2 Lovejoy
Date Observed: Jan 17, 2015 @ 6:30 – 7:20 PM MST
Location: DAS Dark Sky Site in Deer Trail, CO
Mag: 4
Conditions: New moon, intermittent thin wispy clouds.
Comet Position: In Ares, approximately 8° from the Pleiades cluster.
Image: 11 x 240 second exposures, ISO 1600. Tracking was on the comet.
Equipment: Canon T3i prime focus with SV80 APO w/0.8x FFR, Celestron CGEM eq mount. Guided with Orion Magnificient Mini Autoguider.

9. 15P/Finley

Comet: 15P/Finley
Date Observed: December 19, 2014 @ 5:54 – 6:14 PM MST
Location: DAS Dark Sky Site in Deer Trail, CO
Mag: ~9
Moon Phase: New moon
Comet Position: In Capricornus, 1.6° WSW of Mars. (FOV is 1.5° centered on the comet) 20h 51m 40s RA, -19° 23′ 03″ Dec
Image: 8 x 120 second exposures
Equipment: Canon T3i prime focus with Stellarvue SV80ST-25 APO plus Astro-Tech field flattener. Celestron CG-5 eq mount, and Orion Magnificient Mini Autoguider.

 

8. C/2013 A1 Siding Spring

Comet: C/2013 A1 Siding Spring
Date Observed: October 19, 2014 @ 7:13 PM – 8:21 PM MDT
Location: DAS Dark Sky Site in Deer Trail, CO
Mag: ~11
Moon Phase: No moon
Comet Position: 
Image: 1 x 3min exposure.
Equipment: Canon T3i prime focus with 6″ F/9 1370mm Astro-Tech ritchey-chrétien astrograph plus Astro-Tech field flattener. Celestron CG-5 eq mount, and Orion Magnificient Mini Autoguider.

The bright object is Mars; this image was taken approximately 8 hours after the close approach of the two. The comet can be seen at the point of the right diffraction spike with a faint tail. See the full size image on Flickr.

7. C/2014 E2 Jacques

Comet: C/2014 E2 Jacques
Date Observed: September 16, 2014 between 8:30pm – 10:30pm MDT.
Location: DAS Dark Sky Site in Deer Trail, CO
Mag: ~7-8
Moon Phase: 3rd quarter, still below the horizon at time of observation.
Comet Position: In Vulpecula about 20′ from the star Anser
Image: 1 x 5min exposure taken tracking on the stars.
Equipment: Canon T3i prime focus with Stellarvue SV80ST-25 APO plus Astro-Tech field flattener. Celestron CG-5 eq mount, and Orion Magnificient Mini Autoguider.

6. C/2012 K1 Pan-STARRS

Comet: C/2012 K1 Pan-STARRS
Date Observed: December 19, 2014 @ 6:32 – 7:05 PM MST
Location: DAS Dark Sky Site in Deer Trail, CO
Mag: ~10
Moon Phase: New moon
Comet Position: 1.2° NE of NGC 55 (bottom-right of the image). 00h 18m 46s RA, -38° 04′ 06″ Dec
Image: 8 x 120 second exposures
Equipment: Canon T3i prime focus with Stellarvue SV80ST-25 APO plus Astro-Tech field flattener. Celestron CGEM eq mount, and Orion Magnificient Mini Autoguider.

 

 

Comet: C/2012 K1 Pan-STARRS
Date Observed: June 28, 2014 between 9:58pm – 10:16pm MDT.
Location: DAS Dark Sky Site in Deer Trail, CO
Mag: ~8
Moon Phase: New Moon, below horizon.
Comet Position: In Leo
Image: 3 x 90 sec exposure taken tracking on the stars.
Equipment: Canon T3i prime focus with 6″ F/9 1370mm Astro-Tech ritchey-chrétien astrograph plus Astro-Tech field flattener. Celestron CG-5 eq mount, and Orion Magnificient Mini Autoguider

5. C/2011 J2 LINEAR

Comet: C/2011 J2 Linear
Date Observed: March 1, 2014 @ 7:PM
Location: DAS Dark Sky Site in Deer Trail, CO
Mag: ~14
Moon Phase: 
Comet Position: Below Cassiopeia, 00h 09m 07s RA, +57° 14′ 45″ Dec.
Image: Animated gif of 5 x 120 second frames taken tracking on the stars. Animation shows the slight motion of the comet. I’ll note that my scope was out of collimation at the time.
Equipment: Canon T3i prime focus with 6″ F/9 1370mm Astro-Tech ritchey-chrétien astrograph plus Astro-Tech field flattener. Celestron CG-5 eq mount, and Orion Magnificient Mini Autoguider.

 

4. C/2012 X1 LINEAR

Comet: C/2012 X1 LINEAR
Date Observed: December 1, 2013, 4:45-5:30 AM
Location: DAS Dark Sky Site in Deer Trail, CO
Mag: Approximately 8th – 9th magnitude.
Moon Phase: Waxing Crescent, below the horizon.
Comet Position: About 15° above hte horizon in Bootes, the comet forming the bottom point on an inverted equilateral triangle with Izar and Arcturus.
Image: 15 x 3min subs tracking on the comet.
Equipment: Canon T3i prime focus with 6″ F/9 1370mm Astro-Tech ritchey-chrétien astrograph plus Astro-Tech field flattener. Celestron CG-5 eq mount, and Orion Magnificient Mini Autoguider.

3. C/2013 R1 Lovejoy

Comet: C/2013 R1 Lovejoy
Date Observed: December 1, 2013, 5:45 AM
Location: DAS Dark Sky Site in Deer Trail, CO
Mag: ~4-5, not naked eye identifyable.
Moon Phase: 
Comet Position: 
Image: 1 x 5min exposure taken tracking on the comet.
Equipment: Canon T3i prime focus with 6″ F/9 1370mm Astro-Tech ritchey-chrétien astrograph plus Astro-Tech field flattener. Celestron CG-5 eq mount, and Orion Magnificient Mini Autoguider.

First Observation: November 20, 2013 5:31-5:38 AM from Observatory Park in Denver, CO (heavy light pollution). Approximate magnitude 4-5; not naked eye visible at this location. The moon was 2 days past full 35° above the western horizon. Lovejoy was in Ursa Major, forming a right triangle with the comet in the 90° corner, and the stars Phecda in the big dipper and Cor Caroli in Canes Venatici forming the other corners. Alkaid at the end of the big dipper handle lies opposite the hypotenuse from the comet. Image composed of 7 1-min subs  tracking on the comet. Canon T3i prime focus with 6″ F/9 1370mm Astro-Tech ritchey-chrétien astrograph plus Astro-Tech field flattener. Celestron CG-5 eq mount, and Orion Magnificient Mini Autoguider.

2. C/2012 S1 ISON

Date Observed: November 20, 2013, 5:50-5:54 AM
Location: Observatory Park in Denver, CO
Mag: ~4-5 Approx. Not naked eye visible.
Moon Phase: 2 days past full 35° above the western horizon.
Comet Position: 12° above the E horizon, just below and left of Spica, with Mercury below and left of the comet at about equal distance.
Image: 3 x 1min subs taken with 1min intervals between tracking on the comet.
Equipment: Canon T3i prime focus with 6″ F/9 1370mm Astro-Tech ritchey-chrétien astrograph plus Astro-Tech field flattener. Celestron CG-5 eq mount, and Orion Magnificient Mini Autoguider.

1. C/2011 L4 Pan-STARRS

Multiple observations in the evenings between March 16, 2013 to March 29, 2013.

Comet: C/2011 L4 Pan-STARRS
Date Observed: March 23, 2013
Location: Sunset Park in Seattle, WA
Mag: Approximately 4th magnitude. Just naked eye visible.
Moon Phase: —
Comet Position: Western horizon after sunset; near Andromeda
Image: 1 x 10 sec exposure
Equipment: Canon T3i with a EF-S 55-250mm f/4-5.6 IS Lens at 84mm, ISO 800, f/4.5 on a fixed tripod.

Comet: C/2011 L4 Pan-STARRS
Date Observed: March 16, 2013, 8:16 PM
Location: Sunset Park in Seattle, WA
Mag: Approximately 4th magnitude. Just naked eye visible.
Moon Phase: —
Comet Position: Just coming into visibility after sunset on the western horizon.
Image: 4×6 sec exposures over a 2 minute period.
Equipment: Canon T3i with a EF-S 55-250mm f/4-5.6 IS Lens at 250mm, ISO 1600, F9.5 on a fixed tripod.