C/2021 R7 (PANSTARRS)

メタデータ

項目
Designation C/2021 R7 (PANSTARRS)
Type C
Perihelion (tp_cal, UTC) 2021-04-14T11:28:22.085760Z
Orbit solution date (soln_date, UTC) 2022-12-08T23:43:02Z
Obs used 63
NEO -
M1 7.700
K1 14.000
PC -
Discovery observation (MPC, UTC) 2021-09-05T10:13:05.577600Z
Discovery magnitude (MPC) 22.01 w
Discovery observatory (MPC) F52 · Pan-STARRS 2, Haleakala
オスキュレーティング軌道要素
項目
Epoch (epoch_cal, TDB) 2021-11-23.0000000
e 0.99519043
q (au) 5.640615
a (au) 1172.790949
i (deg) 158.854146
Ω (om, deg) 170.145186
ω (w, deg) 139.994299
M (ma, deg) 0.005461

等級

C/2021 R7 (PANSTARRS) · Magnitude (Full range)

散乱 + 全体線形

$$ M_a = (7.384 + 5.410\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

モデル定数

項目
H0 7.384
n 5.410
gf 0.999
gb -0.856
k 1.000
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)
2026-06-01 00:00 20:10:38.23 -39:34:31.7 HIP 99463 11.16
2026-06-01 12:00 20:10:27.81 -39:35:40.3 HIP 99463 13.32
2026-06-02 00:00 20:10:17.30 -39:36:48.9 HIP 99463 15.54
2026-06-02 12:00 20:10:06.70 -39:37:57.4 HIP 99463 17.80
2026-06-03 00:00 20:09:56.01 -39:39:05.7 HIP 99463 20.09
2026-06-03 12:00 20:09:45.24 -39:40:14.0 HIP 99185 21.45
2026-06-04 00:00 20:09:34.39 -39:41:22.1 HIP 99185 20.31
2026-06-04 12:00 20:09:23.45 -39:42:30.1 HIP 99185 19.38
2026-06-05 00:00 20:09:12.42 -39:43:38.0 HIP 99185 18.70
2026-06-05 12:00 20:09:01.32 -39:44:45.8 HIP 99185 18.31
2026-06-06 00:00 20:08:50.13 -39:45:53.4 HIP 99185 18.22
2026-06-06 12:00 20:08:38.85 -39:47:00.8 HIP 99185 18.45
2026-06-07 00:00 20:08:27.50 -39:48:08.1 HIP 99185 18.98
2026-06-07 12:00 20:08:16.07 -39:49:15.3 HIP 99185 19.81
2026-06-08 00:00 20:08:04.55 -39:50:22.2 HIP 99185 20.89
2026-06-08 12:00 20:07:52.96 -39:51:29.0 HIP 99185 22.20
2026-06-09 00:00 20:07:41.29 -39:52:35.7 HIP 99003 20.61
2026-06-09 12:00 20:07:29.54 -39:53:42.1 HIP 99003 18.13
2026-06-10 00:00 20:07:17.71 -39:54:48.4 HIP 99003 15.66
2026-06-10 12:00 20:07:05.80 -39:55:54.4 HIP 99003 13.19
2026-06-11 00:00 20:06:53.82 -39:57:00.3 HIP 99003 10.73
2026-06-11 12:00 20:06:41.76 -39:58:05.9 HIP 99003 8.32
2026-06-12 00:00 20:06:29.63 -39:59:11.4 HIP 99003 6.02
2026-06-12 12:00 20:06:17.42 -40:00:16.6 HIP 99003 4.03
2026-06-13 00:00 20:06:05.14 -40:01:21.6 HIP 99003 3.08
2026-06-13 12:00 20:05:52.79 -40:02:26.3 HIP 99003 4.02
2026-06-14 00:00 20:05:40.37 -40:03:30.8 HIP 99003 6.03
2026-06-14 12:00 20:05:27.87 -40:04:35.1 HIP 99003 8.39
2026-06-15 00:00 20:05:15.31 -40:05:39.1 HIP 99003 10.87
2026-06-15 12:00 20:05:02.67 -40:06:42.9 HIP 99003 13.42
2026-06-16 00:00 20:04:49.97 -40:07:46.3 HIP 99003 16.01
2026-06-16 12:00 20:04:37.20 -40:08:49.6 HIP 98774 15.14
2026-06-17 00:00 20:04:24.37 -40:09:52.5 HIP 98774 14.28
2026-06-17 12:00 20:04:11.47 -40:10:55.2 HIP 98774 13.87
2026-06-18 00:00 20:03:58.50 -40:11:57.5 HIP 98774 13.97
2026-06-18 12:00 20:03:45.48 -40:12:59.6 HIP 98774 14.57
2026-06-19 00:00 20:03:32.38 -40:14:01.4 HIP 98774 15.61
2026-06-19 12:00 20:03:19.23 -40:15:02.8 HIP 98774 17.02
2026-06-20 00:00 20:03:06.02 -40:16:04.0 HIP 98774 18.72
2026-06-20 12:00 20:02:52.75 -40:17:04.8 HIP 98774 20.64
2026-06-21 00:00 20:02:39.42 -40:18:05.3 HIP 98774 22.72
2026-06-21 12:00 20:02:26.03 -40:19:05.5 HIP 98501 21.13
2026-06-22 00:00 20:02:12.58 -40:20:05.3 HIP 98501 19.13