Comet Archive

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P/2018 P4 (PANSTARRS)

メタデータ

項目
Designation P/2018 P4 (PANSTARRS)
Type P
Perihelion (tp_cal, UTC) 2018-11-07T08:17:57.094080Z
Orbit solution date (soln_date, UTC) 2021-04-15T23:33:46Z
Obs used 116
NEO -
M1 11.600
K1 10.000
PC 0.030
Discovery observation (MPC, UTC) 2018-08-08T12:01:59.232000Z
Discovery magnitude (MPC) 20.60 w
Discovery observatory (MPC) F51 · Pan-STARRS 1, Haleakala
オスキュレーティング軌道要素
項目
Epoch (epoch_cal, TDB) 2018-09-13.0000000
e 0.44931114
q (au) 3.666142
a (au) 6.657375
i (deg) 23.112765
Ω (om, deg) 353.110347
ω (w, deg) 8.115551
M (ma, deg) 356.824339

等級

P/2018 P4 (PANSTARRS) · Magnitude (Full range)

散乱 + 全体線形

$$ M_a = (8.263 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

モデル定数

項目
H0 8.263
n 6.000
gf 1.000
gb -0.852
k 0.999
δ90 10.000
パラメータ 記号 範囲 説明
太陽・地球距離が1 AUのときの絶対等級 H0 -5 to 20 彗星の固有の明るさ
測光スロープパラメータ n 2 to 6 太陽距離に対する明るさ変化率
前方散乱非対称係数 gf 0.8 to 1 前方散乱の強さ
後方散乱非対称係数 gb -1 to -0.5 後方散乱の強さ
分配係数 k 0.8 to 1 前方/後方散乱の寄与比
ダスト/ガス明るさ比 δ90 1 to 10 ダスト散乱とガス放射の相対寄与

参考: EPSC-DPS2025-160

天体暦

Date/Time (UTC) RA (J2000) Dec (J2000) Nearest HIP Dist from HIP (arcmin)
2026-02-03 00:00 11:37:12.74 +04:23:53.9 HIP 56724 9.89
2026-02-03 12:00 11:37:05.31 +04:24:25.1 HIP 56724 11.78
2026-02-04 00:00 11:36:57.80 +04:24:56.7 HIP 56724 13.70
2026-02-04 12:00 11:36:50.21 +04:25:28.7 HIP 56724 15.65
2026-02-05 00:00 11:36:42.55 +04:26:01.1 HIP 56724 17.62
2026-02-05 12:00 11:36:34.81 +04:26:34.0 HIP 56724 19.61
2026-02-06 00:00 11:36:26.99 +04:27:07.3 HIP 56724 21.63
2026-02-06 12:00 11:36:19.10 +04:27:41.0 HIP 56724 23.67
2026-02-07 00:00 11:36:11.13 +04:28:15.0 HIP 56724 25.73
2026-02-07 12:00 11:36:03.09 +04:28:49.5 HIP 56724 27.81
2026-02-08 00:00 11:35:54.98 +04:29:24.4 HIP 56724 29.91
2026-02-08 12:00 11:35:46.80 +04:29:59.7 HIP 56724 32.03
2026-02-09 00:00 11:35:38.54 +04:30:35.4 HIP 56569 34.10
2026-02-09 12:00 11:35:30.22 +04:31:11.4 HIP 56569 34.92
2026-02-10 00:00 11:35:21.82 +04:31:47.8 HIP 56569 35.86
2026-02-10 12:00 11:35:13.36 +04:32:24.6 HIP 56378 36.41
2026-02-11 00:00 11:35:04.83 +04:33:01.7 HIP 56378 35.30
2026-02-11 12:00 11:34:56.23 +04:33:39.2 HIP 56378 34.28
2026-02-12 00:00 11:34:47.57 +04:34:17.1 HIP 56378 33.38
2026-02-12 12:00 11:34:38.85 +04:34:55.3 HIP 56378 32.60
2026-02-13 00:00 11:34:30.06 +04:35:33.8 HIP 56378 31.96
2026-02-13 12:00 11:34:21.20 +04:36:12.6 HIP 56378 31.48
2026-02-14 00:00 11:34:12.29 +04:36:51.8 HIP 56378 31.15
2026-02-14 12:00 11:34:03.31 +04:37:31.3 HIP 56378 31.00
2026-02-15 00:00 11:33:54.28 +04:38:11.1 HIP 56378 31.02
2026-02-15 12:00 11:33:45.18 +04:38:51.2 HIP 56378 31.22
2026-02-16 00:00 11:33:36.03 +04:39:31.6 HIP 56235 29.50
2026-02-16 12:00 11:33:26.83 +04:40:12.2 HIP 56235 27.45
2026-02-17 00:00 11:33:17.56 +04:40:53.2 HIP 56235 25.45
2026-02-17 12:00 11:33:08.25 +04:41:34.4 HIP 56235 23.52
2026-02-18 00:00 11:32:58.88 +04:42:15.9 HIP 56235 21.67
2026-02-18 12:00 11:32:49.46 +04:42:57.7 HIP 56235 19.94
2026-02-19 00:00 11:32:39.98 +04:43:39.7 HIP 56235 18.38
2026-02-19 12:00 11:32:30.46 +04:44:21.9 HIP 56235 17.01
2026-02-20 00:00 11:32:20.89 +04:45:04.4 HIP 56235 15.92
2026-02-20 12:00 11:32:11.27 +04:45:47.1 HIP 56235 15.15
2026-02-21 00:00 11:32:01.61 +04:46:30.1 HIP 56235 14.77
2026-02-21 12:00 11:31:51.90 +04:47:13.2 HIP 56235 14.81
2026-02-22 00:00 11:31:42.15 +04:47:56.6 HIP 56235 15.28
2026-02-22 12:00 11:31:32.35 +04:48:40.1 HIP 56235 16.15
2026-02-23 00:00 11:31:22.52 +04:49:23.8 HIP 56235 17.35
2026-02-23 12:00 11:31:12.64 +04:50:07.8 HIP 56235 18.84
2026-02-24 00:00 11:31:02.73 +04:50:51.9 HIP 56235 20.54