Comet Archive

Clear skies!

C/2021 Q4 (Fuls)

メタデータ

項目
Designation C/2021 Q4 (Fuls)
Type C
Perihelion (tp_cal, UTC) 2023-06-10T10:47:21.906240Z
Orbit solution date (soln_date, UTC) 2025-10-03T14:42:16Z
Obs used 558
NEO -
M1 6.800
K1 9.250
PC -
Discovery observation (MPC, UTC) 2021-08-26T07:09:57.139200Z
Discovery magnitude (MPC) 20.07 G
Discovery observatory (MPC) G96 · Mt. Lemmon Survey
オスキュレーティング軌道要素
項目
Epoch (epoch_cal, TDB) 2023-04-14.0000000
e 1.00316029
q (au) 7.564703
a (au) -2393.669779
i (deg) 71.474447
Ω (om, deg) 183.332460
ω (w, deg) 146.998903
M (ma, deg) -0.000483

等級

C/2021 Q4 (Fuls) · Magnitude (Full range)

散乱 + 全体線形

$$ M_a = (0.695 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

モデル定数

項目
H0 0.695
n 6.000
gf 0.998
gb -1.000
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)
2026-02-03 00:00 00:52:28.93 -15:43:09.9 HIP 3970 32.50
2026-02-03 12:00 00:52:37.96 -15:42:34.1 HIP 3970 34.36
2026-02-04 00:00 00:52:47.07 -15:41:58.3 HIP 4240 34.39
2026-02-04 12:00 00:52:56.24 -15:41:22.2 HIP 4240 33.73
2026-02-05 00:00 00:53:05.49 -15:40:46.0 HIP 4240 33.21
2026-02-05 12:00 00:53:14.80 -15:40:09.6 HIP 4240 32.83
2026-02-06 00:00 00:53:24.18 -15:39:33.1 HIP 4240 32.62
2026-02-06 12:00 00:53:33.62 -15:38:56.5 HIP 4240 32.57
2026-02-07 00:00 00:53:43.14 -15:38:19.7 HIP 4240 32.69
2026-02-07 12:00 00:53:52.72 -15:37:42.8 HIP 4240 32.98
2026-02-08 00:00 00:54:02.36 -15:37:05.8 HIP 4240 33.44
2026-02-08 12:00 00:54:12.08 -15:36:28.7 HIP 4240 34.06
2026-02-09 00:00 00:54:21.85 -15:35:51.4 HIP 4240 34.85
2026-02-09 12:00 00:54:31.69 -15:35:14.1 HIP 4426 33.55
2026-02-10 00:00 00:54:41.60 -15:34:36.6 HIP 4426 31.56
2026-02-10 12:00 00:54:51.57 -15:33:59.0 HIP 4426 29.64
2026-02-11 00:00 00:55:01.60 -15:33:21.4 HIP 4426 27.79
2026-02-11 12:00 00:55:11.69 -15:32:43.7 HIP 4426 26.04
2026-02-12 00:00 00:55:21.85 -15:32:05.9 HIP 4426 24.40
2026-02-12 12:00 00:55:32.06 -15:31:28.0 HIP 4426 22.92
2026-02-13 00:00 00:55:42.34 -15:30:50.1 HIP 4426 21.63
2026-02-13 12:00 00:55:52.68 -15:30:12.1 HIP 4426 20.56
2026-02-14 00:00 00:56:03.08 -15:29:34.1 HIP 4426 19.77
2026-02-14 12:00 00:56:13.54 -15:28:56.0 HIP 4426 19.29
2026-02-15 00:00 00:56:24.05 -15:28:17.9 HIP 4426 19.15
2026-02-15 12:00 00:56:34.63 -15:27:39.8 HIP 4426 19.36
2026-02-16 00:00 00:56:45.26 -15:27:01.6 HIP 4426 19.92
2026-02-16 12:00 00:56:55.95 -15:26:23.4 HIP 4521 19.56
2026-02-17 00:00 00:57:06.69 -15:25:45.2 HIP 4521 17.29
2026-02-17 12:00 00:57:17.49 -15:25:07.0 HIP 4521 15.14
2026-02-18 00:00 00:57:28.35 -15:24:28.7 HIP 4521 13.17
2026-02-18 12:00 00:57:39.26 -15:23:50.5 HIP 4521 11.51
2026-02-19 00:00 00:57:50.23 -15:23:12.3 HIP 4521 10.29
2026-02-19 12:00 00:58:01.25 -15:22:34.1 HIP 4521 9.70
2026-02-20 00:00 00:58:12.32 -15:21:56.0 HIP 4521 9.88
2026-02-20 12:00 00:58:23.45 -15:21:17.8 HIP 4521 10.78
2026-02-21 00:00 00:58:34.62 -15:20:39.7 HIP 4597 11.90
2026-02-21 12:00 00:58:45.85 -15:20:01.7 HIP 4597 10.66
2026-02-22 00:00 00:58:57.13 -15:19:23.7 HIP 4597 10.05
2026-02-22 12:00 00:59:08.46 -15:18:45.7 HIP 4597 10.21
2026-02-23 00:00 00:59:19.84 -15:18:07.8 HIP 4597 11.10
2026-02-23 12:00 00:59:31.26 -15:17:30.0 HIP 4597 12.59
2026-02-24 00:00 00:59:42.74 -15:16:52.2 HIP 4597 14.49