Posts Made By: Dave Mitsky

I observed Comet 17P/Holmes again last night from a location near my residence, first with my Burgess Optical 15x70 binocular and then with my 101mm f/5.4 Tele Vue refractor. Conditions were quite good at first but later the transparency started to degrade a bit and frost began to form.

The binocular framed the comet quite nicely with Mirfak, Delta Persei, and Melotte 20. The coma seemed fairly uniform through the binocular, with perhaps a hint of a central brightening.

As it so happened, this was first light for my 13mm Tele Vue Ethos with that particular telescope and the view through the Ethos was simply outstanding. I also used my 35mm TV Panoptic, 19mm TV Panoptic, 13mm TV Nagler T6, 8.8mm Meade UWA, 5mm TV Nagler T6, 4mm Burgess Optical/TMB Planetary Eyepiece, and 3-6mm TV Nagler zoom. This was the first opportunity that I've had to directly compare the 13mm T6 with the Ethos and it was amazing just how small the 82 degree AFOV of the Nagler seemed in comparison to the 100 degrees of the Ethos.

The coma seemed even more uniform than the last time I had seen the comet, which was on Sunday night. I could only make out the comet's pseudonucleus at higher magnifications. The coma almost filled the 22' true field of view at the 4mm setting (135x) of the Nagler zoom and more than filled the 17' TFOV at the 3mm setting (180x). No hint of the faint outer halo was detected.

I also viewed M31, M32, M41, M42 and the rest of the Sword of Orion, M45, M110, the Double Cluster, and Stock 2 (with the Ethos excelling once again) before calling it a night.

Dave Mitsky

On Tuesday night, my friend Tony Donnangelo and I observed Comet 17P/Holmes, Mars (Syrtis Major and the NPC hood were visible), and a few other objects from his backyard using his 102mm f/8 Takahashi FS102 and my 8x42 Celestron binocular. We began sometime after 10:20 p.m. EST (03:20 UT). The transparency was far from ideal, as a front had moved in more quickly than expected, but the seeing was quite good, as was demonstrated by our views of Mars a bit later.

The view through my binocular was excellent, with 17P/Holmes framed very nicely with Mirfak and Melotte 20 (the Alpha Persei Association). The comet has been closing in on Mirfak and had expanded considerably since the last time that I saw it, which was on November 7, and was barely visible to the naked eye. The pseudonucleus was not visible, even at high magnifications, but surprisingly there were subtle hints of a tail. Using the TFOV of a 5.2mm Pentax XL eyepiece as a guide, I estimated the inner coma to be approximately 24' in diameter.

Dave Mitsky

During breaks in the clouds, I observed the comet on Friday night with the ASH 17" f/15 classical Cassegrain and 5" f/5 achromatic finder scope. The coma was bigger than the largest possible true field of view the 17" can produce, which is approximately 26 arc minutes. I could see the pseudonucleus through the 17". A hint of a tail extended from the ragged, trailing end of the coma. There were well over a dozen stars visible within the coma. Magnifications of 118, 144, 162, 202, and 249x were used.

I also viewed 17P/Holmes at low power (18x) with a 108mm f/4.2 Edmund Scientific Astroscan and with my 8x42 Celestron binocular. The comet was visible to my unaided eye only with the use of averted vision.

Dave Mitsky

The transparency left a bit to be desired for a "clear" night but I drove to the Naylor Observatory anyway last night and observed 17P/Holmes with my 8x42 Celestron binocular and the ASH 4 1/8" f/4.2 Astroscan, 5" f/5 achromatic finder scope, and 17" f/15 classical Cassegrain.

The comet was visible to the naked eye with averted vision. The coma almost filled the 47 arcminute field of view that an 8mm Brandon produced with the Astroscan. I could see the pseudonucleus with some difficulty through the 17" at 162 and 202x.

I showed two fellow ASH members M1 and M42 and then Mars. The seeing was not very good, as the CSC had indicated, but by stopping down the 17" to 10" and employing a CC30M magenta filter a bit of detail could be detected. The CM at the time was about 120 degrees so the bland hemisphere of Mars was facing Earth at the time.

Dave Mitsky

It was clear on Friday night but I got a late start so I traveled to the ASH Naylor Observatory instead of to one of the local dark sites.

The transparency was only so-so but I was able to see Comet 17P/Holmes without optical aid. I took some shots of the comet with my Canon EOS Digital Rebel DSLR and observed it with the my 8x42 Celestron binocular, the 4 1/8" f/4.2 Astroscan at 14x (32mm Brandon), the 5" f/5 achromatic finder scope, and the 17" f/15 classical Cassegrain. I could see the pseudonucleus through the 17" at 162x (40mm University Optics MK-70).

I tried to locate another periodic comet currently visible, Comet 8P/Tuttle, which I had forgotten about when I was at the observatory on Thursday night, but I was unsuccessful, even with the help of an Argo Navis. The comet's far northerly position made sweeping with an equatorial mount a bear.

The seeing was rather bad and looking at Mars was a waste of time, even at only 162x. (I didn't bother with stopping the scope down to 10 inches like I did the previous night when the seeing was a bit better.) The "bland" desert hemisphere was facing Earth at the time anyway so it wasn't that much of a loss.

Through the course of the evening I also observed a few bright DSO chestnuts such as M35, M37, M42, M43, M78, NGC 2158, NGC 2169, NGC 2244, NGC 2392, and Beta Monocerotis.

Dave Mitsky

On Thursday evening, the beautifully clear skies that prevailed during the day began to falter. There was no point in driving anywhere dark so I observed Comet 17P/Holmes from my residence through high cirrus clouds. I used my Orion ST80 achromat at 15 and 24x (26 and 17mm Tele Vue Ploessls) at sometime around 0:30 UT and, a bit less than two hours later when it was somewhat more transparent, my 8x42 Celestron and 15x70 Burgess Optical binoculars. The best view of the comet's huge coma was through the 15x70 binocular. That sucker is really getting big!

Dave Mitsky

Here are my deep-sky object lists for December.

Dave Mitsky

One hundred deep-sky objects for December: NGC 891 (Andromeda); IC 342, K6, St23, Tom 5 (Camelopardalis); Be65, IC 1848, K4, Mel15, NGC 896, NGC 1027, St2, Tr3 (Cassiopeia); M77, NGC 788, NGC 835, NGC 864, NGC 908, NGC 936, NGC 955, NGC 958, NGC 1015, NGC 1016, NGC 1022, NGC 1042, NGC 1052, NGC 1055, NGC 1087, NGC 1094 (Cetus); IC 2006, NGC 1084, NGC 1140, NGC 1187, NGC 1199, NGC 1209, NGC 1232, NGC 1291, NGC 1300, NGC 1309, NGC 1332, NGC 1337, NGC 1353, NGC 1357, NGC 1395, NGC 1400, NGC 1407, NGC 1421, NGC 1426, NGC 1440, NGC 1452, NGC 1453, NGC 1461 (Eridanus); NGC 1079, NGC 1097, NGC 1201, NGC 1292, NGC 1316 (Fornax I Galaxy Cluster), NGC 1317, NGC 1326, NGC 1344, NGC 1350, NGC 1360, NGC 1365, NGC 1371, NGC 1374, NGC 1379, NGC 1380, NGC 1381, NGC 1387, NGC 1398, NGC 1404, NGC 1406, NGC 1425 (Fornax); Bas10, Cz8, IC 351, IC 2003, K5, Mel 20, M34, NGC 869, NGC 884, NGC 957, NGC 1023, NGC 1058, NGC 1161, NGC 1245, NGC 1275 (Perseus I Galaxy Cluster), NGC 1333, NGC 1342, NGC 1444, Tr2 (Perseus); M45 (Taurus); NGC 777, NGC 784, NGC 890, NGC 925, NGC 949, NGC 959, NGC 978A/B (Triangulum)

Top ten binocular deep-sky objects for December: M34, M45, Mel15, Mel20, NGC 869, NGC 884, NGC 1027, NGC 1232, St2, St23

Top ten deep-sky objects for December: M34, M45, M77, NGC 869, NGC 884, NGC 891, NGC 1023, NGC 1232, NGC 1332, NGC 1360

Challenge deep-sky object for December: vdB14 (Camelopardalis)

The objects listed above are located between 2:00 and 4:00 hours of right ascension.

Some fellow ASH members and I had planned on taking advantage of a temporary clearing last night to travel to a dark site but the conditions deteriorated a bit locally before we left and we decided that it wasn't worth chancing a hour and 20 minute drive. However, it may have been worth the trip since the cloud cover that rushed in unexpectedly dispersed and we had several hours of clear to partly cloudy skies and the observing site was most likely far enough north to be in the clear the whole time.

When I went outside to unpack my gear, the sky had cleared again so I had a peak at Comet 17P/Holmes through my Burgess Optical 15x70 binocular. A little later I went to a friend's house and we observed the comet through my Celestron Noble 8x42s and his Celestron Ultima 10x50s and Celestron Skymaster 15x70s. We could see the comet naked-eye with direct vision, even from a less than dark location with insufficient time for dark adaptation. The sky seemed to be growing more transparent so after I left I drove to the Naylor Observatory. Unfortunately, the forecast that I saw on the Internet before leaving my friend's house proved to be correct. Clouds moved in from the southwest and the sky was completely overcast by a little more than an hour after I arrived but I did get some observing in nevertheless.

I should have looked at Mars while I had the chance but I wanted to wait until it was a bit higher in the sky. At least I had a chance to see Comet 17P/Holmes again through the ASH Astroscan, StarBlast, 5" achromatic finder scope, and 17" classical Cassegrain. I could just barely make out the psuedonucleus through the 17" at 162 and 202x. It seemed like I could trace out the short tail that extends through the coma as well. Speaking of the coma, it was simply huge. It seemed to be far larger than the more luminous portion of M31 and was distinctly elongated.

A number of winter DSOs also met my gaze, IC 418 (the Raspberry or Spirograph Nebula) in Lepus for example. This rather odd planetary nebula looked pretty good at magnifications from 162 to 404x but I didn't catch any hint of its peculiar "raspberry" color this time around.

During the night, I saw two Geminids serendiptiously. I was planning on trying to do a count for an hour but the oncoming clouds put an end to that notion.

Dave Mitsky

Using a 15x70 binocular, I took another quick look at Comet Holmes this morning shortly after midnight. The coma is still quite easy to see. It was elongated and extremely large.

Dave Mitsky

I spent some time at the Naylor Observatory late on Christmas night. Conditions deteriorated after I arrived but I did manage to observe Mars using the ASH 17" f/15 classical Cassegrain and a variety of eyepieces and color filters (Wratten #21 and 80A and CC30M). Magnifications employed were 202x, 259x, 381x, and 404x. As the seeing was quite variable, I stopped down the scope to 10 and 6 inches at times. With the 10 inch aperture mask in place, I took a few eyepiece projection photographs with a Canon Digital Rebel DSLR and a 32mm Brandon but by then Mars was playing peekaboo with clouds and the shots turned out to be mediocre at best.

Mars was 15.7" in diameter and was shining at -1.6 magnitude during my observing session. The Martian central meridian was about 300 degrees. The NPC, Syrtis Major, Sinus Sabaeus, and Sinus Meridiani were clearly visible during times of good seeing. The latter three areas appear as an indistinct dark vertical line in the attached image.

Dave Mitsky