37175 10 050B 9331 F 20150718181954000 17 75 0226013+066609 56 I+167 10 37175 10 050B 9331 F 20150718182413000 17 75 0226100+066187 56 I+173 10 37175 10 050B 9331 F 20150718182858000 17 75 0226197+065698 56 I+174 10 37175 10 050B 9331 F 20150718183339000 17 75 0226289+065229 56 I+171 10 39459 13 070B 9331 G 20150718164819000 17 75 0010506-165750 56 I+183 10 39459 13 070B 9331 G 20150718164939000 17 75 0010508-165771 56 I+173 10 39459 13 070B 9331 G 20150718165100000 17 75 0010510-165791 56 I+156 10 39459 13 070B 9331 G 20150718165220000 17 75 0010511-165809 56 I+168 10 39459 13 070B 9331 G 20150718165341000 17 75 0010513-165828 56 I+179 10 39459 13 070B 9331 G 20150718165501000 17 75 0010515-165846 56 I+185 10 39459 13 070B 9331 G 20150718165622000 17 75 0010517-165867 56 I+171 10 39459 13 070B 9331 G 20150718165745000 17 75 0010518-165886 56 I+161 10 Skynet 4B r3 19689 88 109C 9331 F 20150718182024000 17 75 0225248+066416 56 I ---------------------------------------------------------------------- 0.51-meter F/6.3 Dall-Kirkham + CCD + Astrometrica + UCAC4 Warrumbungle Obs., NSW, Australia 31.27517 S, 149.19453 E, 552 m ASL What these numbers mean: http://www.satobs.org/position/IODformat.html ---------------------------------------------------------------------- Another session on extremely distant objects using the 0.51-m telescope of Warrumbungle (MPC Q65), Australia. Targets were the same two Chang'e CZ-3C boosters I have reported on earlier. 88-109C (Skynet 4B r3) was imaged as a stray, showing a clear periodic brightness variation. I previously reported that 2010-050B, the Chang'e 2 r/b, appeared to be steady. Turns out this is not true. Yesterday I imaged it at 279 000 km distance, only a few hours away from its perigee, resulting in a longer trail than during earlier imaging sessions. Suddenly, the trail dissolves into dots: a very rapid brightness variation. Each 30-second exposure trail has 2-3 dots, indicating a period of ~15 seconds. Brightness varies from invisible to mag +16.7. Positions above are for the first dot on each image, and the times therefore might be a few seconds off. During earlier imaging sessions the object was at a much larger distance (typically twice that of yesterday), resulting in shorter trails on the images. As a result, the individual flashes merged into one single trail. The other object, 2013-070B, the Chang'e 3 r/b, showed a clear slow brightness variation with (like earlier sessions) a period of ~7 minutes and an amplitude of 3 magnitudes. Same obs as above, in MPC format: NET UCAC-4 2010-050B C2015 07 18.76382 02 26 01.34 +06 39 39.2 16.7 R Q65 2010-050B C2015 07 18.76682 02 26 09.95 +06 37 07.2 17.3 R Q65 2010-050B C2015 07 18.77012 02 26 19.65 +06 34 11.1 17.4 R Q65 2010-050B C2015 07 18.77337 02 26 28.91 +06 31 22.5 17.1 R Q65 2013-070B C2015 07 18.70022 00 10 50.59 -16 34 30.1 18.3 R Q65 2013-070B C2015 07 18.70115 00 10 50.81 -16 34 37.7 17.3 R Q65 2013-070B C2015 07 18.70208 00 10 50.98 -16 34 44.8 15.6 R Q65 2013-070B C2015 07 18.70301 00 10 51.14 -16 34 51.3 16.8 R Q65 2013-070B C2015 07 18.70395 00 10 51.32 -16 34 58.1 17.9 R Q65 2013-070B C2015 07 18.70487 00 10 51.46 -16 35 04.6 18.5 R Q65 2013-070B C2015 07 18.70581 00 10 51.65 -16 35 12.0 17.1 R Q65 2013-070B C2015 07 18.70677 00 10 51.82 -16 35 18.9 16.1 R Q65 Updated approximate orbits: 2010-050B = Chang'e 2 booster Perigee 2015 Jul 18.903168 TT = 21:40:33 (JD 2457222.403168) Epoch 2015 Jul 18.0 TT = JDT 2457221.5 Find_Orb M 347.15832 (2000.0) n 14.21848828 Peri. 174.04751 a 364223.437 km Node 222.84485 e 0.2235324 Incl. 40.31290 q 282807.693 km Q 445639.181 km P 25.32d From 15 observations 2015 June 15-July 18; mean residual 0".524. Chang'e 2 rb 1 00000U 15199.00000000 .00000000 00000-0 00000-0 0 08 2 00000 40.3115 223.0638 2287930 173.6459 347.5636 0.03899403 06 2013-070B = Chang'e 3 booster Perigee 2015 Jul 26.203864 TT = 4:53:33 (JD 2457229.703864) Epoch 2015 Jul 18.0 TT = JDT 2457221.5 Find_Orb M 187.38159 (2000.0) n 21.04110860 Peri. 37.69650 a 280473.021 km Node 142.73740 e 0.7471244 Incl. 25.27110 q 70924.7791 km Q 490021.264 km P 17.11d From 32 observations 2015 June 26-July 18; mean residual 0".507. Chang'e 3 rb 1 00000U 15199.00000000 .00000000 00000-0 00000-0 0 08 2 00000 25.2694 142.9522 7459802 37.6893 187.4024 0.05825874 01 Under the influence of strong Lunar perturbations, 2010-050B's apogee and perigee are currently rapidly decreasing: 2010-050B Chang'e 2 rb ---------------------------------------------------------------------- EPOCH perigee apogee a ecc inc period ---------------------------------------------------------------------- 07.0 May 2015 352827 551615 452221 0.2197903 41.13389 35.03d 14.0 Jun 2015 310299 494264 402281 0.2286525 40.68457 29.39d 09.0 Jul 2015 291037 457018 374028 0.2218830 40.64094 26.35d 18.0 Jul 2015 282808 445639 364223 0.2235324 40.31290 25.32d ---------------------------------------------------------------------- In 72 days time, perigee has come down 70 000 km and apogee 106 000 km. Over a longer term the orbit evolution is strongly chaotic, notably under the influence of close Lunar encounters. - Marco ----- Dr Marco Langbroek - SatTrackCam Leiden, the Netherlands. e-mail: sattrackcam_at_langbroek.org Cospar 4353 (Leiden): 52.15412 N, 4.49081 E (WGS84), +0 m ASL Cospar 4355 (Cronesteyn): 52.13878 N, 4.49937 E (WGS84), -2 m ASL Station (b)log: http://sattrackcam.blogspot.com Twitter: _at_Marco_Langbroek ----- _______________________________________________ Seesat-l mailing list http://mailman.satobs.org/mailman/listinfo/seesat-lReceived on Sun Jul 19 2015 - 07:19:38 UTC
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