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Observations of Molniya 3-3

Dan Laszlo and Jeff Brower, two observers from Colorado, USA discovered a new flasher. The object in question is Molniya 3-3 (75-105 A), a rather high and thus difficult object. The first observations happened by accident. They were able to indentify the object from the positions measured. Subsequent efforts to observe it confirmed the identification. Here is what Dan has to say about his three observations (some editing done by BDP).

The satellite was seen on 3 nights, 3/5, 3/23, and 3/25 UT. Specular flashes were not seen on the night of 3/23/95 UT, but when seen on the other 2 nights, their period seems to match the period of the other flashes. On 3/5/95 UT, specular flashes were crudely timed at about 11 seconds period, and persisted as long as we followed the object, about 20 minutes. On 3/25/95 UT, only 3 specular flashes were seen in the midst of the pass, alternating with "fainter" nonspecular flashes. Regarding timing, the 3 specular flashes were simultaneous with, and presumably obscured, the "brighter" nonspecular flashes. The timeline for 3/25/95 shows this evolution in appearance over the course of the pass.

Date: March 23 1995 0223 to 0230 UT

Instrument: 300mm f/5 Newtonian reflector, alt/azimuth mount, 32mm Plossl, field 1.1deg

Sky location: Note, satellite was not seen on three previous nights attempts with 11x80 binoculars, searching between 3 Monocerotis and Epsilon Monocerotis. Satellite was not seen on first observation attempt tonight with the telescope as it passed 3 Monocerotis, predicted azimuth 204.4 deg, elevation 35.5 deg. It was seen, within 2 minutes of prediction, as it passed between Epsilon Monocerotis and SAO 113683(star magnitude 5.8), within 0.5 degree of predicted azimuth 204.9 degrees, elevation 51.8 degrees. Direction: Initially nearly vertical, up with respect to horizon, increasing westward trend, with estimated less than .2 degree west trend per 1 degree vertical over this period.

Rate of motion: About 3.5 flash periods per field, yields approximately 1 degree per 40 seconds.

Flash period: 5 cycles, peak to peak, in 60 seconds, +/- 0.5 seconds, yields period 12.0 sec +/- 0.1 seconds.

Flash description: Two minor flashes, approx mag 10, at 1 and 0.5 sec before onset of major flash. Major flash with symmetrical crescendo/decrescendo over 1 second, peak approximately magnitude 8.

Acknowledgments: Thanks to Jeff Brower for providing the 4K elsets for the search, and then providing the name for 75105A; thanks to Mike Prochoda for the foresight to note the time of passage on March 5 by the Rosette Nebula cluster NGC 2244 , which made the initial identification possible. Summary of two observations in standard format:

Station Location: 1 mile northwest of Briggsdale Colorado USA lat 40:40N; long 104:22W

Date: March 25 1995 02:11:30 to 02:15:23 UT

Sky Location: Acquired within 0.5 degree of target site, azimuth 204.3 degrees; elevation 52.3 degrees, satellite passing between star SAO113723 magnitude 8.4 and star SAO113740 magnitude 8.7, about 1 degree west of Epsilon Monocerotis.

Flash period: 11.7 seconds +/- 0.03 s = 93.6 seconds +/- 0.2 s / 8 periods.

I selected the eight best defined periods, before 02:14:00 UT. Visual description of pass, aided by review of audio tape with WWV time signals. Consider the magnitude estimates rough.

02:11:30 Acquired satellite
02:12:15.8 8.5 magnitude flash
02:12:26.3 7th magnitude flash
02:12:39.3 8.5 magnitude flash
02:12:49.7 7th magnitude flash
02:13:02.6 8.5 magnitude noted double flash (about 0.5 sec)
02:13:13.6 Specular flash, magnitude 4-5
02:13:25.8 8.5 magnitude double flash
02:13:37  (specular flash seen by my 7 year old)
02:13:49  (missed this one)
02:14:00.0 Specular flash, magnitude 4-5
02:14:13 8.5 magnitude flash becoming prolonged, timing difficult
02:14:25.7 Flash, not specular, magnitude uncertain
02:14:38 8.5 magnitude flash, duration 1 second, timing difficult
02:14:48 8.5 magnitude flash, duration 1 second, timing difficult
02:15:00  (missed this one)
02:15:10 onset 9 magnitude flash, duration 2 seconds
02:15:21 onset 9 magnitude flash, duration 2 seconds.  Lost it after this.

Summary of observation in standard format (too bad the complexity can't show!):

75-105 A 95-03-05 03:54:00 DJL 11 1.0 1 11
75-105 A 95-03-23 02:23:00 DJL 60 0.5 5 12.0
75-105 A 95-03-25 02:11:30 DJL 93.6 0.2 8 11.7+/-0.03

For the 3/23/95 UT and 3/25/95 UT observations, the telescope permitted detection of flashes that would have only briefly been above my threshold of detection with the 11x80 binoculars. Viewing then would likely have been relatively easy with a 200mm, or even 150mm objective. The strobelike, specular flash that first drew my attention to the object on 3/5/95 UT was about 2nd magnitude and seen with the naked eye! It was readily visible in binoculars that night as the specular flashes were fainter, but persisted at least 20 minutes. The specular flashes on 3/25/95 UT should have been easily visible in binoculars, and the brighter nonspecular flashes may have been also, given the proper place to look. When the flashes were at least 10th magnitude, tracking was not difficult, but they faded and ended my observation. It may have brightened again. I'll have to get some help with a wider field instrument to prevent losing the object in the future. To summarize, the view has been extremely variable night to night (even within a single pass!), with consistency only in track and flash period.

BTW, finder charts were constructed using points from Orbitrack plotted on a Redshift star chart, with stars to 9th magnitude to assure the correct field.

Jeff Brower located a line drawing and a picture of a typical Molniya satellite, both of which you can see below. The prototype Molniya satellite looks like a six-bladed fan, or a flower, composed of a central cone, and 6 long rectangular solar panels radiating from the base of the cone, plus two small dish antennas on stalks. Jeff tells me the solar panels are independently steerable to maximize efficiency, so this bird has many potential variables. He found the radar cross section is about 5 square meters.

This has all been much more interesting than a pinpoint meteor or passing aircraft, which were my first impressions on 3/5. Twilight beginning to interfere with my opportunity for observations this week. A preliminary run through predictions puts my next chance to see it at similar altitude (10000km) in August 1995, and similar looks from Europe in Fall and Winter, 1995-6. It could make an intriguing target, particularly for the video equipped observers in your group. I'd choose a large aperture to capture the complexity of the pass.

Dan Laszlo, some editing done by BDP, thanks to Jeff Brower for the illustrations

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Next: Determination of Rotation Up: Flash 92 Previous: Observational Flashes