Comet Panstarrs (C/2011 L4)

C/2011 L4 (PANSTARRS) is a non-periodic comet discovered in June 2011 that became visible to the naked eye when it was near perihelion in March 2013. It was discovered using the Pan-STARRS telescope located near the summit of Haleakalā, on the island of Maui in Hawaii. Comet C/2011 L4 probably took millions of years to come from the Oort cloud. After leaving the planetary region of the Solar System, the post-perihelion orbital period (epoch 2050) is estimated to be roughly 106000 years. Dust and gas production suggests the comet nucleus is roughly 1 kilometer (0.62 mi) in diameter. (from Wikipedia)


My original plan was Windy Hill on Skyline, but I did not have time so I stopped at bayland park trail near HW237. The sunset looked beautiful but that was a bad news , as the “beauty” came from clouds that covered lower sky from SW to NW. Anyhow I took a few pictures, even though I did not expect to capture the comet. Today when I checked , to my surprise I saw the comet behind the cloud. The core was bright and a very short  fan shaped tail seemed barely visible. I also setup a binoculars but could not see it visually.
I wish I had stayed longer (I left at 7:50) and captured more photos.

The following 3 photos were taken at 19:47, 19:50, 19:55, with Canon T3i and 70-200mm nikon zoom lens at 70mm. ISO: 400,exposure time: 1s. Cropped from original, no post processing.


Panstarrs at Suntset


Panstarrs at Suntset


Panstarrs at Suntset


Late afternoon Cirrus clouds on the north changed my original plan to Skyline, so my kids and I drove to Anderson Lake in Morgan Hill to stay away the clouds. My decision was paid off, the sky was crystal clear except very few clouds on the lower western sky.
Using crescent moon as the reference it was easy to locate the comet. I first spotted it at 19:50 in my 8×50 binoculars, 4 degrees left to the moon. It had a moderate bright core with a very tiny, light, fan shaped tail (due to bright background). The best view was between 19:55 and 20:00. The bright core looked like a water-drop (or upside down ice cream core), I think the core itself was near round, the “triangle” was brightest part of the tail. The long, narrowed fan shaped tail stretched about 1/2 of moon diameter (direct vision), or 3/4 of moon diameter (avert vision), at PA of 20 degrees. Both core and tail were white. With naked eye, it was barely visible, no tail could be seen.


Comet Panstarrs (C/2011 L4) and Moon
03/12/2013 19h48m

Comet Panstarrs and Moon: 1s at ISO400. 70-200mm zoom lens at 70mm. Cropped and enhanced for contrast.  The comet was ~4 degrees due left to the crescent (1 day old) moon. The scene was breathtaking even without comet – the hair thin crescent moon hanging low over the crystal clear, colorful sunset sky.


Comet Panstarrs (C/2011 L4) and Moon
03/12/2013 19h59m

Comet Panstarrs and Moon: 15s at ISO400. 70-200mm zoom lens at 200mm. Cropped and enhanced for contrast. This resembled what was visible through my 8×50 binoculars – very bright core with fail tail.


Comet Panstarrs (C/2011 L4) and Moon
03/12/2013 20h00m

Comet Panstarrs and Moon: 30s at ISO400. 70-200mm zoom lens at 200mm. Cropped and enhanced for contrast.


Comet Panstarrs (C/2011 L4)
03/12/2013 20h00m

Comet Panstarrs: cropped from the above image and then enhanced for contrast. 30s at ISO 400. The core was very bright and elongated, with ~30′ fan shaped tail.


The sky did not look promising at sunset, when the Cirrus clouds hang over the western and northern sky. Regardless I setup my camera at bayland park trail again. The clouds over the coastal range dispersed and the sky was almost completely clear. I was able to spot the comet with binoculars at 17:52PM, since I did not bring my tripod mount for binoculars, I spent rest time taking some pictures.


Comet Panstarrs (C/2011 L4) and Moon
03/13/2013 20h02m

Cropped and enhanced for contrast.


Comet Panstarrs (C/2011 L4) and Moon
03/13/2013 20h12m

Cropped and enhance for contrast. Crescent Moon and comet over silicon valley evening sky.


Comet Panstarrs (C/2011 L4)
03/13/2013 20h07m


The sky did not look so good when I left home, the high and mid clouds were pushed from North and the lower N and W horizon was covered with some clouds. I decided to go to Anderson Lake in Morgan Hill again to avoid the clouds, without knowing what the condition would be, because there was my last chance before the full Moon. It looked like I would be washed out when I arrived there, but I was a little bit lucky again – the clouds dispersed quite a bit when night fell though they still persisted above the horizon. Finding the comet was not an easy task since I switched to my telescope and to my non-goto mount. I had to use my binocular to find the closest bright star (DeltaAND).  I finally spot it with my naked eyes which made finding the comet breeze. I took some pictures with my AT72ED, I did not have a lots of time so the result did not match my expectation, partially due to the haze and passing clouds.

Picture saved with settings applied.

Comet Panstarrs (C2011/L4)
03/24/2013 20h28m

This is a stack of 9x5s photos taken with T3i through AT72ED, processed with DeepSkyStracker. ISO1600. It clearly shows the bright core and ~15′ fan shaped tail.

Picture saved with settings applied.

Comet Panstarrs (C2011/L4)
03/24/2013 20h25m

This is a stack of 10×2.5 photos, ISO1600, processed with DeepSkyStacker.


Went out in the evening to capture Panstarrs and Andromeda. Most late afternoon high clouds disappeared when sun set, but haze and lingering clouds still covered N and W horizon, together with lights from nearby baseball field, made only the brightest part of comet and galaxy visible.


Comet Panstarrs (C2011/L4) and Galaxy Andromeda
18x15s ISO 800

This is a stack of 18x15s, ISO 800, Nikon 70-200mm lens at 70mm. Stack with DSS, processed with FitsWork.


Comet Panstarrs is moving North and has become a morning comet, since the viewing condition is much better than the evening. On 3AM morning I headed out to Windyhill Open Space parking lot on Skyline Blvd,  the sky was  crystal clear, no annoying haze or high clouds, except light dome from Silicon Valley towards North and East.

I took lots of close up photos with my AT72ED on CGEM mount, as well as wide angle photos with 70-200mm zoom lens, to show the comet and Galaxy Andromeda.


Comet Panstarrs (C2011/L4)
30s x 46, ISO 1600


Comet Panstarrs (C2011/L4)
60s x 5, ISO1600

I believe that I was able to see the comet with my naked eye without much difficulty, it looked  like a small and dim star but with fluffy feel  (I could also feel that it was not a “point” ). With my 8x50mm binoculars, the comet had a star like nucleus which was about 7m magnitude. The nucleus was surrounded by mist coma which shows almost no condensation. Nucleus and Coma were much fainter than when the comet was first appeared in the evening sky a month early. The tail was straight, looked similar to Coma – dim, mist and no condensation, it was about 20″ long, pointing 30 above the horizon.

4/17/2013 (Aloha from Maui)

I went to Maui for vacation with my family during spring beak. I did not particularly planned for any star gazing activity until I learned that Panstarr is hosted on Halealkala Observer story which is on summit of Haleakala NP. I suddenly realized that I might be able to visit on of the darkest sites on earth for star gazing. I contacted Becky Sydney, the president of Maui Astronomy Club, expressed my desire to have  star gazing at Maui, and the summit. She provided detailed and  useful information on how to observe sky on island, she also introduced me to Rob Ratkowski – president of Haleakala Amateur Astronemer which owns a observing site on the summit.I communicated with Rob via email and also met him in person during our stay. He lent me his equatorial tracking mount so that I could take some pictures with my DSLR.

On the very next day after arriving Maui, my family drove up to Haleakala National Park for sightseeing. I could not believe that we were 10000 feet above the sea level in merely 38 miles drive. Overlook of volcanos from several lookout areas was stunning and unforgettable. When I arrived parking lot on the  summit I saw 4 big domes, shining under blue sky and white clouds.

The weather in next few days was not good at all, cloudy and even rainy on some days, and I did not even get a chance to watch beautiful Hawaiian beach sunset.

On April 17th, the sky turned clear but it was very windy. I did not plan to go to the summit initially, but after considering the weather forecast (not as accurate though) and moon set time, I rushed out with my old son to the summit.

I arrived at the summit at 1AM, just after moon set. The sky was crystal clear and dark, it was the first time that Milky Way looked so bright.  But it was cold and windy, I felt chilly even with my sweater on. I spent about 20 min to observe a few eye candies – Omega Cen, Alpha Cen, Bet Cen, Southern Cross and Milky Way.

I was planning to take some close up as well as wide angle images of various objects. But it was so windy that the tripod was too shaky to use big lens, so I gave up close up imaging after failed a few times.


Milky Way on Haleakala Observatory
Canon T3i, 18mm, ISO 1600, 8x1min

After finishing up above pictures, I just realized that it was time to take some pictures of comet Panstarrs. A quick check show that it was rising behind the domes. It did not take me too much time to decide what to shot – Panstars over Panstarr dome (I am not sure whether the dome hosts Panstarr or not, any how it is still a rare opportunity to take comet Panstarrs at Haleakala Observatory site).


Comet Panstarrs over Panstar
Canon T3i, 35mm, ISO 1600, 60s, tracking mount


Comet Panstarrs over Panstarrs Dome
Canon T3i, 50mm, ISO 1600, 60s x 5, tracking mount


Comet Panstarrs over Panstarrs Dome
Canon T3i, 50mm, ISO 1600, 60s x 5, tracking mount

With my 8×50 binoculars, a 7m stellar nucleus  (simiar to HD1598) was surrounded by a mist of thin clouds with no condensation, and avert vision detected  a 30′ tail (15-20′ with direct vision) pointing to HD1598. The tail was thin (density), with no condensation (which looked same as the mist cloud surrounding the nucleus) for most part of it, and gradually faded  for the rest.


I took the advantage of clear sky and marine layer  which reduced the sky glow from the valley, at Windy Hill OSP parking lot on Skyline Blvd. The sky was clear with excellent seeing, weather was dry and warm since it was above the marine layer. Wind was calm. I took picture of Panstarrs and Lemmon.


Comet Panstarrs

40 x 60″, ISO1600, AT72ED on CGEM


I took this picture on E Dune Road to Henry Coe, the sky was great and there was not much light solution there. Two tails were visible in the picture, one bright straight tail, and another fail one on the opposite side.


Comet Panstarrs

20 x 90″, ISO1600, AT72ED on CGEM


Again I took the picture of Panstarrs on E Dune Road to Henry Coe. This time I was shocked by its long, straight and bright tail, it became much stronger than last time; and there was aslo fan shaped faint tail on the opposite side.


Comet Panstarrs

61 x 105″, ISO1600, AT72ED on CGEM