Comet P/2008 S1 = 2015 G1 (Catalina-McNaught) Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE:地球近傍天体広域赤外線 探査衛星、以前のWISE:広域赤外線探査衛星)の赤外線画像から天体が見つかった。 G. V. WilliamsによってP/2008 S1の検出観測であることが確認された。 MPC 79350のWilliamsの予報に対し、Delta(T)は、-0.11 dayであった。 検出位置は次のとおり、 2015 UT R.A. (2000) Decl. Mag. Apr. 5.67044 19 06 05.07 - 9 09 03.4 19 5.93301 19 06 52.62 - 9 08 24.8 6.06443 19 07 16.52 - 9 08 05.7 6.19571 19 07 40.09 - 9 07 44.4 6.58957 19 08 51.91 - 9 06 49.5 6.78656 19 09 27.81 - 9 06 19.9 6.98355 19 10 03.84 - 9 05 51.0 7.18042 19 10 39.83 - 9 05 21.2 7.18055 19 10 39.85 - 9 05 20.5 7.44312 19 11 27.97 - 9 04 41.3 7.77140 19 12 28.30 - 9 03 50.9 8.09955 19 13 28.66 - 9 03 00.2 8.09967 19 13 28.73 - 9 02 59.9 8.23096 19 13 52.96 - 9 02 40.6 連結軌道要素、位置推算表は次のとおり、 Orbital elements: P/2008 S1 = 2015 G1 (Catalina-McNaught) Epoch 2008 Oct. 21.0 TT = JDT 2454760.5 T 2008 Oct. 1.82968 TT MPCW q 1.1902378 (2000.0) P Q n 0.14624994 Peri. 203.63122 +0.69448150 +0.67738293 a 3.5678418 Node 111.39020 -0.61160608 +0.73335656 e 0.6663984 Incl. 15.10161 -0.37899004 +0.05779726 P 6.74 From 76 observations 2008 May 2-2015 Apr. 8, mean residual 0".5. P/2008 S1 = 2015 G1 (Catalina-McNaught) Epoch 2015 June 27.0 TT = JDT 2457200.5 T 2015 July 1.75534 TT MPCW q 1.1967322 (2000.0) P Q n 0.14579357 Peri. 203.66504 +0.69460067 +0.67740140 a 3.5752833 Node 111.36381 -0.61152464 +0.73329908 e 0.6652763 Incl. 15.07377 -0.37890305 +0.05830782 P 6.76 From 76 observations 2008 May 2-2015 Apr. 8, mean residual 0".5. P/2008 S1 = 2015 G1 (Catalina-McNaught) Epoch 2022 Apr. 11.0 TT = JDT 2459680.5 T 2022 Mar. 31.43243 TT MPCW q 1.1889783 (2000.0) P Q n 0.14630712 Peri. 203.67730 +0.69479120 +0.67709183 a 3.5669122 Node 111.37035 -0.61125114 +0.73360067 e 0.6666645 Incl. 15.09478 -0.37899503 +0.05810945 P 6.74 From 76 observations 2008 May 2-2015 Apr. 8, mean residual 0".5. Ephemeris: P/2008 S1 (Catalina-McNaught) Date TT R. A. (2000) Decl. Delta r Elong. Phase m1 2015 03 10 17 52 50.3 -09 42 18 1.6805 1.8127 81.0 32.7 18.7 ... 2015 03 25 18 32 24.2 -09 31 23 1.4457 1.6938 85.7 35.9 18.1 ... 2015 04 02 18 55 10.4 -09 17 18 1.3293 1.6319 87.8 37.7 17.7 ... 2015 04 08 19 13 10.2 -09 03 16 1.2468 1.5865 89.1 39.1 17.5 2015 04 09 19 16 15.3 -09 00 39 1.2334 1.5790 89.3 39.4 17.4 2015 04 10 19 19 21.8 -08 57 58 1.2202 1.5716 89.5 39.6 17.4 ... 2015 04 16 19 38 33.8 -08 40 21 1.1436 1.5277 90.5 41.1 17.1 ... 2015 04 24 20 05 44.0 -08 13 22 1.0491 1.4714 91.4 43.1 16.8 ... 2015 05 09 21 02 10.1 -07 15 10 0.8988 1.3747 92.0 47.2 16.2 (CBET 4090、MPEC 2015-G17)