Europa

I just came back inside after an hour of stargazing. it's COLD. But wow, the sky is extremely steady tonight. With my 80mm refractor at 170x the airy disks were sharp and steady, and the innermost diffraction ring was seen as three steady, solid arcs.

I looked at Jupiter and its four moons. The clouds were beautiful, but the absolute highlight was the moon Europa. When I started looking at 9.30pm I could only see three moons and an incredibly tiny black dot on top of Jupiter's clouds. but as I kept watching at 170x, at the border of Jupiter's clouds a tiny brighter spot started to appear. Within minutes it was a tiny bright dot, growing out of Jupiter. So Europa was crossing over Jupiter, throwing its shadow on Jupiter, and I caught it just in time to see the moon's disk moving away from Jupiter. I kept watching it as its shadow moved and eventually disappeared. I missed the exact moment of that last event though, as I was also looking at M42 and M43 in the meantime.

M42 and M43 had their beautiful shape as usual. The last time I had seen them was years ago with my 254mm telescope in California, in a much darker location, so it came a bit as a surprise that I could only see 4 stars of the trapezium with my 80mm telescope here. So I didn't even see E and F (both around magnitude 10.3). The A, B, C and D stars were all bright though (but then the dimmest of them is only around magnitude 8). With my 254mm telescope I remember I could always easily see 7-8 stars, which means I had no trouble reaching magnitude 14.5. Without nebulosity, high in the sky, I actually have notes that say I also saw magnitude 15.5 stars with it.

I only stayed outside for an hour, came back inside at 10.30pm, and only looked at these objects.

Tonight was the first night I used my new TeleVue 2x Powermate. The refractor doesn't reach focus if I place it in front of the diagonal, so I have to place it after the diagonal. Its barrel cannot be moved completely in it, so the setup is not exactly parfocal as I had intended. Compared to my Meade 2x barlow it is very heavy, but the resulting image is brighter, has more contrast and less flaring. Jupiter and M42 just looked darker and not as sharp with the barlow. But because switching the setups takes time, I didn't do a very detailed comparison. I did notice that the magnifications do not seem to match. It looks like the setup for the barlow results in a slightly lower magnification than expected.

Vulpecula

This evening I wanted to focus on the tiny constellation of Vulpecula near Cygnus and Lyra. I started observing using the 80mm refractor around 20:30h EST. The seeing was fair (5/10).

M27 (Dumbbell Nebula): Bright planetary nebula. Elongated, but I didn't see a pinch, nor the m9 star near its west edge. Several nearby stars were visible at 32x, but significantly more at 86x. The Lumicon UHC filter improved contrast, but didn't show more details. M27 can easily be found by star hopping from 13 Vulpeculae. I didn't actually see the dim stars of Vulpecula in the Rigel Quickfinder, but 13 Vulpeculae itself can be found by mentally extending the line between Gamma Lyra and Albireo for 3/4 the distance between those two stars.

Stock 1: I didn't spend much time observing this open cluster, as I only encountered it while star hopping from M27 to the Struve binaries. I observed it at 32x, and should revisit it next time.

Struve 2455: I found it more difficult to resolve than Struve 2457, but both were readably separated even at 32x. Struve 2455 consists of a m7.4 and m8.5 star, separated 6.6", while Struve 2457 consists of m7.5 and m9.0 stars, separated 10.3".

Struve 2457: As with Struve 2455 I didn't detect the difference in color between the binary components, but the magnitude difference made them attractive anyway. Struve 2455 and 2457 easily fit in the FOV of the 7 mm Nagler (86x), being separated by just half a degree. The position angles of the two binaries differ by almost 180 degrees. Using the barlow only deteriorated the view, because of the seeing and because the faintness of the secondary, possibly made worse by the barlow itself.

Struve 2445: A triple, with a m7.2 and m8.9 star separated 12.6", and a third m8.9 separated 2.4'. Even more easy to observe than Struve 2457.

Stopped observing at 22:15h, because Struve 2445, 2455 and 2457 moved behind a tree in the west, and the clouds started rolling in.

Io's Shadow

I have just returned from a very quick observation session of planet Jupiter and its moons at 00:30 (August 16). After so many years, I had to see it. It had rained all day, is partially clouded and the seeing is poor. The telescope (80mm refractor) was still warm as I used it immediately after moving it from indoor to the 14 ℃ outdoor, so the quick guess of 4/10 isn't too accurate. I observed Jupiter and its moons at 32x and 86x. The seeing prevented the use of the barlow at 171x. The magnification of 86x provided the best balance between contrast, image size and stability.

Three of Jupiter's moons were visible. Europa & Callisto on one side and Ganymede on the other side. Also visible was the obvious shadow of a moon crossing Jupiter, Io's. I didn't see Io transit though. Jupiter's cloud bands NEB, SEB and STB were clearly visible as well.

DewBuster Temperature Sensor

As I mentioned in a previous post, it looks like the DewBuster temperature sensor is busted after all these years of non-use.

After following the troubleshooting instructions at the DewBuster site, I contacted Ron about the issue. He quickly provided three possible causes of the issue, one of which was "The contacts inside the sensor jack is oxidized. Try putting a few drops of alcohol on the sensor plug and plugging/unplugging repeatedly to wipe the contacts clean.".

Being the easiest to test, I immediately tried it and indeed, this resolved the issue! The telescope/ambient temperature sensor operation is back to normal. Ron made my day.

Nagler

Today I received the 7mm TeleVue Nagler, which gives me 86x with the 80mm refractor and 357x with the 254mm SCT. The seeing was once again excellent, but I only observed for about an hour this time, with the 80mm refractor and mostly the same objects as I did for the past couple of nights. With this eyepiece the Lumicon UHC filter is actually useful on M57 at 86x. I could clearly see the darkening in the center of this planetary nebula.

I could also split Epsilon Lyrae at 86x, and at 171x using the 2x barlow it's a beauty.

I also looked at Polaris this evening, which is a binary star with magnitude 2.0 and 8.2 stars separated by 18.4". The glare introduced by the barlow made it actually easier to observe the secondary at 86x than at 171x. Because I use the Meade 4000 series 2x Apochromatic Barlow (#140) also for planetary imaging, I wonder how much contrast I loose for that.

Although I find barlows rather clumsy for visual observing, maybe I should try to sell it and get a TeleVue 2x Powermate instead. The barlow doesn't have any obvious poor baffling or paint. It's just that its coating is quite reflective in comparison to my TeleVue eyepieces.

Neighbor

Tonight my neighbor Rafael joined me and my 80mm refractor with his Celestron AstroMaster 90AZ telescope. I first showed him M57, Epsilon Lyrae and Albireo with my refractor before we tried to use his 90mm refractor.

I found it impossible to adjust the finder correctly, and the mount was difficult to handle. Possibly it can be improved by rebalancing the telescope somewhat, but we didn't try. Both eyepieces were ok (40mm and 20mm, Plossls I guess), but the telescope's collimation seems way off, as all stars looked like comets even with my 19mm Panoptic. Like with my 80ED, collimation seems to be done through adjustment of the focuser, so we'll have to try to fix it.

We also observed M31 and the double cluster using the 70mm binoculars.

After Rafael went home, I observed Globular Cluster M56 in Lyra. I could only find it by star hopping, although I found out later that I was pretty close with my initial Rigel Quick Finder method . It's just that M56 is much dimmer in the 80mm than I had expected. It looked like a faint fuzzy ball.

I really ought to start making some drawings.

O∑403 Cyg

I only just had moved the 80ED outside when I checked the seeing this evening, so even though it looked a little worse then yesterday's, it may actually have been similar.

This evening I set up the 10" LX200GPS telescope to further explore the seeing. I had it cool down for at least 1.5 hours. I tweaked the collimation slightly, but it still isn't spot on.

I observed M13, resolving it for a large part, M57, in which I could not detect the central star, but only the one just outside the nebula and Epsilon Lyrae, which as expected could be resolved without problems.

Pushing the 10" using the SR4mm to a magnification of 625x, with ease it cleanly resolved both 0.8" separated magnitude 7.4 and magnitude 7.6 components of O∑403 Cyg. There was a third dimmer star approximately 10 arc seconds from this tight double star, which I later realized to be the magnitude 10.0 ∑2657 Cyg (separation 11.6"). No doubt I could have resolved double stars separated at the SCT's Dawes limit of 0.5" this evening.

Although the seeing was excellent, the star images did wobble around a bit, which I suspect was caused by the ALT-AZ tracking of the telescope and not by movement of the deck. I have to investigate that further.

I also experimented with the Barlow today. Using it behind the diagonal works for both the 80ED and the SCT. The 80ED setup becomes somewhat unstable with it though. Also with both telescopes it makes the view dimmer than expected, and I suspect significant light loss when using it (vignetting or reflections).

Incidentally the LX200GPS initially misbehaved this evening for the first time ever. With one of the two Pyramid power supplies its controller lighted up without displaying any text, but seemingly operating. Then when I switched to the other power supply, the Dec motor ran away at full speed upon initialization. Luckily I managed to turn off the telescope before damage occurred. After that the telescope behaved normal again, albeit the pointing accuracy was poor even after I had just aligned it using automatic alignment. Hence I didn't use the GOTO functionality this evening.

This evening also demonstrated that I like the quick grab-and-go setup of the 80ED really a lot more than the lug-and-slow setup of the LX200GPS. The LX200GPS really ought to be used with a permanent setup.

Seeing Surprise

Tonight I took the 80ED for another ride on the PORTA II. Because I was curious about the collimation of the telescope, I also used the 31 years old SR 4mm for a 150x magnification, and boy was I in for a surprise.

Not only was the telescope's collimation still spot on, but the seeing produced a textbook diffraction pattern! A 10 on the pickering scale (10/10).

• Globular Cluster M13 in Hercules: Even at 31x this fuzzy ball is clearly brighter towards its center, but at 150x it became somewhat mottled, hinting that it indeed consists of stars.
  
• Double Star Albireo: The 4mm only made the colors duller, so it wasn't a good match for this one.
  
• Planetary Nebula M57 in Lyra: This time I also tried the nebula filter with the 9mm, which led to a better contrast and stronger hints of darkening in the center. This object requires a higher magnification than 31x of course.
  
• Quadruple Star Epsilon Lyrae: I could split all four members with easy at 150x. The view was tack sharp with diffraction patterns.
  
• Open Cluster M29 in Cygnus. At 150x, I could see the magnitude 12 stars inside the quadrilateral formed by the four brightest stars. This bodes well for the limiting magnitude near zenith, regardless the light pollution.
  

I really ought to get some extra eyepieces, and put that LX200GPS to some use as well!

The New Deck

After many years of low observing activity, I recently decided to get back to visual observing. Instead of having to lug out the LX200GPS and wait for it to cool down, I figured a grab-and-go set-up using my 80ED would likely be more successful.

Because I had bought that telescope as a wide field imaging telescope mounted on top of the LX200GPS, and the Orion Paragon-Plus XHD tripod that I originally had purchased as an alternative mount many years ago has been a huge disappointment, I purchased a Vixen PORTA II mount. Now that is a nice mount for this telescope!

With ease I observed the following objects this evening, all found within seconds after pointing the Rigel Quick Finder in the expected direction:

• Double Star Mizar
  
• Quadruple Star Epsilon Lyrae
  
• Globular Cluster M13
  
• Globular Cluster M92
  
• Planetary Nebula M57
  
• Double Star Albireo
  

Now it helps that my 19mm Panoptic results in a 2.2° field of view with this telescope, but at 31x the magnification and contrast is rather low for a full enjoyment of the view, so I am really tempted now to buy a few extra eyepieces.

Note that it could be the low magnification, but the seeing looked considerably better than I expected from the DC area. I really ought to get out more often, and try the LX200GPS as well!

The setup used this evening was:

• Orion 80ED
  
• Vixen PORTA II Mount
  
• ScopeStuff dovetail bar and cradle rings
  
• Dew Buster with Dew-Not dew removers for the objective and eyepiece
  
• William Optics 2" Diagonal
  
• Televue Panoptic 19mm
  
• Rigel Quick Finder
  
• Pyramid PS9KX 5A/7A Power Supply
  

The DewBuster was turned off though, because it looks like its temperature sensor is busted after all these years of non-use. I still have to investigate that further.

April Fool's Night

I obtained a tripod mounting block for use with mounting rings and used it to mount the 80ED refractor (with 2" diagonal and 19mm eyepiece, 31x) on the Paragon-Plus XHD tripod. The scope still is out of balance, but a bit less than before, making this combination a little more comfortable to use. This time I also attached the Rigel QuikFinder.

From my light polluted patio, I observed M97 with the refractor. I could only detect it by using the UHC filter. It looked like a featureless roundish smudge of a few arcminutes across near a triangle of stars. M97 forms a right triangle with two if these stars.

Globular Cluster M3 was easy to find. It is visible as round nebulosity that gets dimmer towards the edge. In the same view, two bright magnitude 6 and 7 stars are visible, and M3 itself sits in the "center of mass" of three other stars (mag 8.4, 9.8 and 10.6). M3 is about 3' across in the refractor. No stars of M3 itself were resolved. I am rather surprised that even though I am observing from my patio and high clouds are sometimes reducing the visibility, the limiting magnitude at this magnification is about 11 (towards the east, at about 50 degrees altitude).

At 22:30 I observed Saturn in the Western sky. Its moons Titan (mag 8.4) and Rhea (mag 9.8) were easily visible. I did not detect any other moons. Besides the rings, Saturn did not show any details. At 31x I could not detect the cassini division (which is not surprising with such a low magnification). The effects of atmospheric diffraction were visible when Saturn was slightly out of focus.

I also observed Castor. I could not resolve this double stars (mag 1.9 and 2.9 separated 2.5") at this magnification. I could easily see the mag 9.8 star 72" away and a mag 10.4 star 3' away.

Double star nu-Draconis was an easy target as well. These mag 4.9 stars are 62" separated. They appear white. I was confused for a moment, thinking I was looking at the wrong object, but then I realized magnitude 6.5 GSC 3893:353 is a non-existent object. After realizing that, the star field made sense (field of view is 2 degrees across with this configuration).

At 00:25 I also observed Albireo while it was rising above the East horizon. Even though it was only 10 degrees above the horizon, the orange and blue components were easily separated (34"). This double star is always a joy to observe.

Finally, I observed Jupiter and four of its brightest moons in the Soutern sky. Two cloudbands of Jupiter were obvious, but no other details on Jupiter were observed. Again I noticed the effects of atmospheric diffraction on Jupiter, which surprised me at 50 degrees altidude. I didn't notice color fringe, but had trouble focussing Jupiter. It more looked like a focus problem of my own eyes than bad seeing. I wonder if the Panoptic is to blame.

Polaris and the Ring Nebula

This evening I mounted the 80ED refractor on a Paragon-Plus XHD tripod. Attaching the 2" diagonal and 19mm eyepiece result in a tail-heavy combination that is too much out of balance for comfortable use. I need to get a tripod mounting block for use with mounting rings so I can balance it properly.

I pointed the telescope towards Polaris and had no trouble splitting this binary at 31x. Later I also observed the Ring Nebula M57. It was not difficult to find, even though I had not mounted the Rigel QuikFinder. At 31x it was not more than a tiny smudge from my light-polluted patio. Adding a UHC filter improved the contrast somewhat.

Airplane!

An airplane heading for SJC while imaging the M81/M82 mosaic. This is a single 60 second frame through the V filter.

NGC 1502

NGC 1502 on December 3, 2004. A 10 minute exposure (20x30s) through a V filter using the 80ED. The camera was cooled to -15°C.

I also imaged it with an I filter. I still have to perform photometry.

The Double Cluster in Perseus

NGC 869 and NGC 884. Mosaic of two images taken on December 3, 2004 through a V filter with the 80ED telescope. One of 57x30s and the other of 31x30s. The camera was cooled to -15°C.

Click the image to see the full mosaic.

Equipment

Telescopes

• Oberwerk 10.5x70mm Ultra Series binoculars. I selected 10.5x instead of the more common 15x because I assumed this would allow me to use it without tripod. It also has a larger exit pupil distance. However, although these are great binoculars, I regret not buying the 15x variant instead. It's too heavy to not use with a tripod anyway, I find the 10.5x magnification too low and, more importantly, the exit pupil diameter of the 10.5x variant is too big. Since 2010 I use it with an Orion binocular mount on the Orion XHD Paragon Plus tripod I originally bought for the 80ED. Its weight is really pushing the limits, especially when viewing near zenith, because of the poor design of the binocular attachment on that mount. This binocular mount is far from perfect, but it does make observing with the binoculars more convenient;
  
• My main telescope is a 254mm f/10 Meade UHTC LX200GPS. It has the standard electrical focuser and primary mirror lock. A nice feature of this telescope is the upgradable firmware (older versions and history can be found here). To reduce the slewing noise and load on the gears, I use a maximum slewing speed of only 1 degree per second;
  
• For wide field imaging, I have an 80mm f/7.5 Orion 80ED. I usually mount it on top of the main telescope;
  
• 7x50 binoculars of an unknown brand bought mid-nineties. The optics were never properly aligned, but I wasn't actively observing in this period anyway. In 2001 I picked up the observing again but when I bought the LX200GPS, a GOTO telescope, I stopped using it again. I replaced it in 2008 with 10.5x70mm binoculars;
  
• 115mm f/9 Newton telescope bought in 1981 through Gerard Keijzers from N.J.R.S for a 10% reduced price from Ganymedes in Amstelveen, The Netherlands. I still remember my excitement when Gerard helped me setting up this telescope and I viewed through its 20mm eyepiece for the first time. It has a aluminum OTA and equatorial mount on a wooden tripod.
  It's a decent telescope but it has its flaws. The equatorial mount is inadequate for the OTA. The slightest breeze or touch causes the OTA to wobble and it takes several seconds to dampen. Also its 30mm finder is of very poor quality and I rarely used it. The telescope is rebranded as "Vesta", but I think it is a predecessor of the now discontinued Celestron Firstscope 4.5" Newton on a CG-3 mount (model 31044) with .965 inch Huygens 20mm (magnification 45x) and 6mm (magnification 150x) eyepieces. Later I also added a Huygens Mittenzwey 9mm (magnification 100x) and a Symmetrical Ramsden 4mm (magnification 225x). The ones I used most were the 20mm and the 9mm eyepieces. From my old drawings it is clear that my eyes and the telescope optics once were pretty good. I did see the casinni division and a cloud belt on Saturn with it for example. Nowadays the mirrors are very much in need for a recoating;
  
• 40mm refractor. I was really my brother's, but I used it for many years instead. It had a cardboard OTA, wooden ALT-AZ mount and probably because of the heavy use by me its achromatic doublet developed an air bubble between its crown and flint lenses which made it a poor performer. I also ruined the single Huygens eyepiece at one point, but continued to use it. In addition I ruined most of the negatives of my family's pictures in my Sun spot viewing sessions (usually at sunset), but I don't think anyone but me ever realized that.
  

Cameras

• SBIG ST-7XE NABG CCD camera. This is a dual CCD camera with a full-frame NABG 765x510 (9x9μm) pixel Kodak KAF-0401E imaging CCD and a full-frame ABG 192 x 164 (13.75x16μm) pixel TC-211 CCD tracking CCD. Mine can cool up to -40°C from abient without using the water cooling. I usually set it to -35°C. In San Jose, CA, this means that the CCD temperature is around -25°C (-13F) on a "cold" winter night, and around -15°C (5F) during summer.
  
• SBIG CFW8A color filter wheel. This automatic filter wheel has room for 5 1.25 inch filters, which is 5 too few, because besides the standard R, G, B and clear filters (and an empty slot), I also own Bessel V and I filters for photometry and narrowband H-alpha, OIII and SII filters.
  
• SBIG AO-7 Adaptive Optics. This is a high speed tip-tilt mirror system. My laptop limits it to 30 corrections a second. I usually use it at 7Hz - 15Hz.
  
• Philips ToUCam Pro webcam for planetary imaging;
  
• Meade Superwedge. Instead of the standard knobs, I use replacements from Scopestuff so I don't have to use tools.
  
• Meade f/6.3 and f/3.3 focal reducers.
  
• Cable (Radioshack)
  
• Jumpstarter (Walmart). I never even tried to use the telescope with internal batteries. From the start, I used a 12V 17AH battery.
  
• 25ft serial cable for connecting the telescope to the laptop (Radioshack).
  
• Springy Thingy (parts from Home Depot)
  
• Pizza pan. I found it a pain to try to put the telescope on its tipod for ALT-AZ. As I didn't want to spend $95 on a scopesaver table, I bought a $2.95 pizza pan instead, drilled an off-center hole in it and marked the outline of the telescope base on it.
  
• Dew shield (Orion)
  
• Quick Rigel finder
  
• Collimation thumbscrews (Scopestuff)
  
• Balancing kits and weights (Scopestuff)
  
• Dew heater. I bought the convenient Dew Buster. To recover the costs, I made all the heaters (telescope, finder and eyepiece) myself.
  Case (JMI).
  
• 350 Watt inverter (Walmart).
  
• The next thing I will buy is the ASO optical cleaning kit. After almost one year of use, the corrector of the SCT is dirtier than my car's wind-shield.
  

I generally use this equipment in the following combination:

• Telescope - focuser - camera
  This combination fits through the forks and results in a f/10 system. The image scale is 1.028"/pixel??? in 1x1 binning mode and field of view is 10'x9'.
  
• f/6.3 reducer - focuser - camera
  
• Focuser, F/3.3 reducer, 15mm spacer, camera
  
• Focuser, F/3.3 reducer, 30mm spacer, camera
  This results in a F3.3 system.
  
• Telescope - focuser - AO-7 - camera
  F/11.3???
  
• Telescope - Focuser - f/6.3 reducer - AO-7 - camera
  This results in a f/7 (1774mm) system. The image scale is 1.04"/pixel in 1x1 binning mode and the field of view is 13.3'x8.8'. 1.033avg-1.030+1.035??
  
• Telescope - Focuser - f/6.3 reducer - 15mm spacer - AO-7 - camera
  

The image scales were determined using actual images. I used the formula:
focal length [mm] = 205 * pixel size [micrometers] / image scale ["/pixel]
to compute the effective focal length.

My reasons for not using other combinations,are:

• Telescope - AO-7 - camera.
  This combination fits through the forks, but without microfocuser it is pretty useless.
  
• Telescope - f/6.3 reducer - focuser - AO-7 - camera
  This results in a f/4.9 (1253mm) system. The image scale is 2.098"/pixel??? and the field of view is 26.7'x 17.8'. This combination results in off center vignetting with a brightness difference of about 30%. For this reason, I will not use this combination anymore.
  

Problems

Although the LX200GPS is an incredibly value for the money, it does have a few problems.

• The fork mount is heavy. swing
  
• The OTA of my telescope is not mounted parallel to the fork arms. When I put it in polar home position and rotate the telescope back and forth in RA, I will never find position (by adjusting the declination) where the stars move around a center.
  
• The optical axis is not aligned with the mechanical axis of my optics. When I use the f/3.3 reducer or the f/6.3 reducer with a big spacer, the vignetting is off center. Coma is visible in one corner when I use the f/3.3 reducer.
  

Hardware Issues

A list of issues encountered:

• The OTA of my telescope is not mounted parallel to the fork arms. When I put it in polar home position and rotate the telescope back and forth in RA, I will never find position (by adjusting the declination) where the stars move around a center.
  
• The optical axis is not aligned with the mechanical axis of my optics. When I use the f/3.3 reducer or the f/6.3 reducer with a big spacer, the vignetting is off center. Coma is visible in one corner when I use the f/3.3 reducer.
  

• Internal reflection caused by the visual back.
  
• Telescope didn't fit in the JMI case.
  
• The handy microfocuser mounting thumbscrews that were included with the JMI case ruined the original visual back and many of my images.
  

Planetary Nebula M76

M76 on October 30, 2004. Four 30 minutes exposures combined for a total exposure of 2 hours.

Equipment used: 254mm SCT @ f/6.1, ST-7XE @ -15C, AO7 @ 7.5Hz (RMS wander 0.1x0.1, activation level 10%, bump 0.30s, dither 3), 656.3/4.5 nm H-alpha filter. Location: San Jose, CA.

The Moon

The Moon. This image is a mosaic of 8 frames captured on September 6th, 2004 around 1am PST. Each frame was exposed 0.2 seconds through a 656.3/4.5 nm H-alpha filter.

Equipment used: 254mm SCT @ f/6.1, ST-7XE @ -15C. Location: San Jose, CA.

Click the image to see the full 1650x1650 mosaic.

Crab Nebula (M1)

2004-09-05: 40 minute exposure (4x600s) through H-alpha filter. Camera cooled to -15°C.

Minor Planet (1316) Kasan

Asteroid 1316 Kasan was discovered on November 17, 1933 by the Russian astronomer Grigoriy Nikolaevich Neujmin (1886-1946). He is credited with the discovery of 74 asteroids, including 951 Gaspra and 762 Pulcova. He also discovered or co-discovered the periodic comets 25D/Neujmin, 28P/Neujmin, 42P/Neujmin, 57P/du Toit-Neujmin-Delporte and 58P/Jackson-Neujmin.

This movie was created from 11 images, each having an exposure of 2 minutes, taken over a 35 minute timespan on the night of 2004-08-19 (around 11PM PST). Each image was taken through an infrared filter. 1316 Kasan is marked at the start of the sequence and can be seen moving towards the West (North is up and East is to the left). At the time the images were taken, the asteroid distance from the earth was almost 1 AU, and its distance from the Sun was 1.8 AU.

The bright star on the upper-left of this movie is magnitude 9 SAO 71737 in the constellation Cygnus. The star immediately east of the asteroid is of magnitude 12.5. Because the images were not obtained using a V filter, but using an I filter, the differential photometric magnitude of 16.2 for the asteroid is not accurate (but it is still close to the expected magnitude of 15.8).

The center of the images as reported by the telescope was RA 21h 48m 48s, DEC +38d 14' 19''. A plate solution found RA 21 48m 43.78s, DEC +38d 13' 30.7''. The image scale is 2.35 arcsecs/pixel (the whole image is about 15' x 10'). During the 35 minute sequence, the asteroid moved almost 21 arcseconds.

The animation is noisy because I did not have matching bias/dark frames, nor did I have flat frames. I downscaled other bias/dark frames, and used strong dead/hot pixel removal to reduce the remaining noise.