Sunday 28 April 2013

PANSTARRS and Polar Light - Finland, March 2013

From 17 to 24 March I was in Finland, having fun in the snow at the Arctic circle. We stayed at Basecamp Oulanka at Juumajärvi, 66.26 N, from where we did snowshoe hikes, a husky sled tour, some cross-country skiing, and a trip to a world-famous bird shelter in order to see the Golden Eagle.

Of course, when going to the Arctic circle you hope for Aurora Borealis - the Northern Lights. I had seen Northern Lights before, from the Netherlands (where it is rare but on occasion can be seen), and it was stunning. So my hopes were high for an even better Arctic display. In addition, comet PANSTARRS was slowly moving out of the solar glare around that time. My secret mission: to get an image of the comet with Northern lights.

Mission accomplished, on the very first evening:

click image to enlarge

The photograph is a stitch of two images made with the EOS 60D and a Tamron 17-50mm at 17mm. It was made in late evening twilight of March 17th, the start of an evening with incredible Northern Lights. An M1-class solar flare on the 15th resulted in an earth-directed CME which arrived at the 17th - our first evening in Finland. The result: astonishing Aurora all over the sky, with two especially intense periods between 20-21h local time and around local midnight. The first peak was very colorfull, with a.o. deep purples in addition to green. During the second peak near midnight, it was mostly green Aurora It was very lively, significantly changing on sub-second scales. Rays, dancing curtains, multiple corona's, it was all visible. Seeing Northern Lights in Orion was quite special too.

This all with friendly temperatures of -25 C... As I repeatedly worked the camera with my gloves off, my fingers got numbed, resulting in some images later that night where the camera had moved during exposure, because I hadn't thightened the clampscrews of the tripod head enough. I also used one of my woolen gloves to put the Aputure timer in, as the batteries suffered from the cold. The camera itself help up remarkably well though.

During the first peak I took pictures from the nearby lake Juuma: during the second peak I photographed from the basecamp itself, using the wooden chalets to create some scenic foregrounds. Lenses used were a SamYang 3.5/8mm semi fish-eye, and the 17-50mm Tamron. Here are some pictures (exposures range from 2 to 10 seconds:

click images to enlarge

I took a number of series for a time lapse, resulting in this movie (put it on HD and full-screen: it is 1200x800 pixels):

As it turned out, that night was the only night with aurora that week - but what a splendid show it was! The local Fin people claimed it was the best show of the season.

The next evening, I targetted comet 2011 L4 PANSTARRS in evening twilight, using the Zeiss 2.8/180mm. The following image is a stack of 9 images of 1s each, taken from an unguided stationary tripod:

click image to enlarge

Just before leaving for Finalnd, I already had some views of the comet from (near) my home town Leiden in the Netherlands as well. This image was shot on March 12th from the Cronesteyn polder just east of Leiden:

click image to enlarge

After I returned from Finland, I took a last picture of the comet in the evening of April 2nd, when it was close to M31, the Andromeda Galaxy. This image is a stack of 21 images of 1s each taken with a SamYang 1.4/85mm at F2.8. I had to do quite some image processing, as the images were suffering from light pollution:

click image to enlarge

Tuesday 23 April 2013

PAN and Mentor 4 in March

Finally, an update on my observing activities in March. With apologies that it took so long.

In this post, early March observations of the classified geostationary satellites PAN and Mentor 4 will feature. In a second post following this one, I will report on some non-satellite observations: comet PANSTARRS and a fabulous display of Aurora borealis which I observed from Finland.

PAN and Mentor 4

As I noted on the blog before, weather has been extremely bad here since mid November 2012. Many nights were clouded, we had unusual amounts of snow, and spring set in very late (in fact, only last week).

click image to enlarge

The few clear nights we had, usually coincided with a bright moon in the sky. As wintertime is a bad time for LEO objects at latitude 52N  (the visibility window is very short, restricted to twilight) the focus is on objects in GEO during this season: but that necessitates clear moonless nights....

On the evening of March 4 I did an attempt, which was cut short when clouds and haze moved in. The pictures came out bad, but I did manage to image PAN (2009-047A) and Mentor 4 (2009-001A), as can be seen in the picture above. Mentor 4 is a SIGINT: PAN probably is too.

PAN was moved again in December-January, this time taking up position at 42.5 E close to the commercial telecom sat Nigcomsat 1R.

Since its launch in 2009, this enigmatic satellite has frequently moved, and this is unusual. PAN was stationed at 33.0 E from late 2009 to May 2010 and then was moved to 38.0 E. It was moved again to 49.0 E in December 2010, followed by a move to 44.9 E in the spring of 2011. Then it was relocated to 39.1 E in the summer of 2011 and next moved to 52.5 E somewhere between late October 2011 and January 2012. In May 2012 it was moved back to 38.0 E. In December 2012, it moved to 42.5 E. No doubt it will move again in the future, perhaps in May as December and May are frequently the months the satellite is moved.

Note: the listed positions for PAN are based on privately archived TLE's for the satellite. The TLE source is Mike McCants and the TLE's are based on amateur observations of the satellite, notably by Greg Roberts (S-Africa), Peter Wakelin (UK), Ian Roberts (s-Africa) and me (Netherlands).

Friday 12 April 2013

The discovery of asteroid 2013 GM21

I am way behind with my reporting on this blog, for which I apologize. I still have satellite observations from early March to report, as well as (somewhat off-topic) observations of comet 2011 L4 PANSTARRS and spectacular Aurora borealis (Northern Lights) from Finland mid March. For various reasons, I did not come to that yet. Maybe coming weekend...

Meanwhile, a short report on my latest asteroid discovery: 2013 GM21, which was published in the DOU MPEC K13-G54 today (Apr 12, 2013: look for object K13G21M).

On  April 6th, I was on my own initiative (and successfully) trying to get follow-up observations on three objects (2013 EZ102, 2013 EB103 and 2013 EC103) which Krisztian Sarneczky and I discovered in the Konkoly survey from MPC 461 (the 60-cm Schmidt of Konkoly, HU) mid-March. I was "remotely" using the 81-cm Schulman telescope of the Mt. Lemon Sky Center (MPC G84) for that, one of the telescopes in the SSO Network.

In the images that should (and did) contain 2013 EZ102, I found two other moving objects. Both were unidentified - i.e., they were not in the MPCOrb asteroid database of the IAU Minor Planet Center and could be new discoveries! So they were submitted to the MPC with the temporary designations LaMa515 and LaMa516.

One of these (LaMa515) turned out to have been observed by another observatory just days before, so that one was not a new discovery: the other observatory alas beat me to it.

 photo 2013_GM21_LaMa516_6APR_G84_anim_zps6ec97a6c.gif
click image to enlarge

The second object however, a mag +19.5 to +20 object I temporarily designated LaMa516 moving quite close to 2013 EZ102 in the images, turned out to be truely new: my observations of April 6th were the first! It can be seen in the blink above, which shows you a small part of the April 6th discovery images. 2013 EZ102 is in the images too.

I next obtained new images, based on a very rough search orbit fit, on April 7th, 8th and on April 11th, again using the 81-cm telescope of MPC G84. As a result, it was formally MPEC-ed today by the MPC as 2013 GM21: my second asteroid discovery using a "remote" telescope! And my 69th asteroid discovery in total (and 5th in 2013, the other four being in the Konkoly survey. For a full list of my discoveries see here).

The asteroid is a borderline Maria family main belt asteroid. With H=16.8, it is an estimated 1.5 km large. It has the following orbital elements (source: MPC):

2013 GM21

Epoch 2013 Mar. 29.0 TT = JDT 2456380.5   MPC
M 351.06235              (2000.0) 
n   0.24233744     Peri.   39.90632             
a   2.5479390      Node   164.25356             
e   0.0734092      Incl.   17.12483
q   2.3608968      T       2456417.38101 JDT 
P   4.07           H   16.8 
From 13 observations 2013 Apr. 6-11.

click images to enlarge

As can be seen in the orbital plots, the orbit is well inclined to the ecliptic. I discovered it when it was in opposition and close to perihelion of its orbit, these two factors combining in a maximum brightness for the object. This is basically the same situation as with my earlier discovery 2012 SM58.