C/2020 M3 (ATLAS)

メタデータ

項目 値
Designation C/2020 M3 (ATLAS)
Type C
Perihelion (tp_cal, UTC) 2020-10-25T14:58:23.448000Z
Orbit solution date (soln_date, UTC) 2022-04-23T03:12:26Z
Obs used 2344
NEO Yes
M1 14.600
K1 6.000
PC -
Discovery observation (MPC, UTC) 2020-06-27T13:57:10.627200Z
Discovery magnitude (MPC) 18.89 o
Discovery observatory (MPC) T08 · ATLAS-MLO, Mauna Loa
オスキュレーティング軌道要素
項目 値
Epoch (epoch_cal, TDB) 2020-11-26.0000000
e 0.95270763
q (au) 1.268249
a (au) 26.817195
i (deg) 23.473528
Ω (om, deg) 71.250235
ω (w, deg) 328.446314
M (ma, deg) 0.222681

等級

C/2020 M3 (ATLAS) · Magnitude (Full range)

散乱 + 全体線形

$$ M_a = (14.015 + 2.681\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

モデル定数

項目 値
H0 14.015
n 2.681
gf 0.993
gb -1.000
k 0.999
δ90 1.000
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

残差 (区間線形)

$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$

開始日 (UTC) 終了日 (UTC) a b
2012-01-10 2020-08-06 -14.0320 +4.994
2020-08-06 2020-10-25 +30.0861 -5.641
2020-10-25 2021-06-10 +4.2695 -2.068

log10 r = log10(太陽距離/AU)、Δ = 地球距離(AU)

天体暦

Date/Time (UTC) RA (J2000) Dec (J2000) Nearest HIP Dist from HIP (arcmin)
2026-09-20 00:00 13:18:01.50 +12:10:54.6 HIP 64881 3.84
2026-09-20 12:00 13:18:08.24 +12:10:00.3 HIP 64881 5.22
2026-09-21 00:00 13:18:15.01 +12:09:06.3 HIP 64881 6.85
2026-09-21 12:00 13:18:21.79 +12:08:12.4 HIP 64881 8.58
2026-09-22 00:00 13:18:28.59 +12:07:18.7 HIP 64881 10.36
2026-09-22 12:00 13:18:35.40 +12:06:25.2 HIP 64881 12.18
2026-09-23 00:00 13:18:42.24 +12:05:31.9 HIP 64881 14.02
2026-09-23 12:00 13:18:49.09 +12:04:38.8 HIP 64948 14.68
2026-09-24 00:00 13:18:55.95 +12:03:45.9 HIP 64948 13.95
2026-09-24 12:00 13:19:02.83 +12:02:53.2 HIP 64948 13.45
2026-09-25 00:00 13:19:09.73 +12:02:00.6 HIP 64948 13.21
2026-09-25 12:00 13:19:16.64 +12:01:08.3 HIP 64948 13.25
2026-09-26 00:00 13:19:23.57 +12:00:16.2 HIP 64948 13.57
2026-09-26 12:00 13:19:30.51 +11:59:24.3 HIP 64948 14.14
2026-09-27 00:00 13:19:37.47 +11:58:32.6 HIP 64948 14.94
2026-09-27 12:00 13:19:44.44 +11:57:41.1 HIP 64948 15.94
2026-09-28 00:00 13:19:51.42 +11:56:49.8 HIP 64948 17.09
2026-09-28 12:00 13:19:58.41 +11:55:58.7 HIP 64948 18.38
2026-09-29 00:00 13:20:05.42 +11:55:07.9 HIP 64948 19.77
2026-09-29 12:00 13:20:12.44 +11:54:17.3 HIP 65104 21.15
2026-09-30 00:00 13:20:19.48 +11:53:26.9 HIP 65104 21.67
2026-09-30 12:00 13:20:26.52 +11:52:36.7 HIP 65104 22.34
2026-10-01 00:00 13:20:33.58 +11:51:46.7 HIP 65104 23.15
2026-10-01 12:00 13:20:40.64 +11:50:57.0 HIP 65104 24.08
2026-10-02 00:00 13:20:47.72 +11:50:07.5 HIP 65104 25.12
2026-10-02 12:00 13:20:54.81 +11:49:18.3 HIP 65104 26.25
2026-10-03 00:00 13:21:01.90 +11:48:29.3 HIP 65104 27.47
2026-10-03 12:00 13:21:09.01 +11:47:40.5 HIP 65104 28.76
2026-10-04 00:00 13:21:16.13 +11:46:52.0 HIP 65104 30.11
2026-10-04 12:00 13:21:23.25 +11:46:03.7 HIP 65104 31.52
2026-10-05 00:00 13:21:30.38 +11:45:15.7 HIP 65104 32.98
2026-10-05 12:00 13:21:37.52 +11:44:27.9 HIP 65292 32.82
2026-10-06 00:00 13:21:44.67 +11:43:40.4 HIP 65292 31.19
2026-10-06 12:00 13:21:51.83 +11:42:53.1 HIP 65292 29.59
2026-10-07 00:00 13:21:58.99 +11:42:06.1 HIP 65292 28.04
2026-10-07 12:00 13:22:06.16 +11:41:19.4 HIP 65292 26.55
2026-10-08 00:00 13:22:13.33 +11:40:32.9 HIP 65292 25.11
2026-10-08 12:00 13:22:20.51 +11:39:46.7 HIP 65292 23.74
2026-10-09 00:00 13:22:27.69 +11:39:00.8 HIP 65292 22.46
2026-10-09 12:00 13:22:34.88 +11:38:15.1 HIP 65292 21.28
2026-10-10 00:00 13:22:42.08 +11:37:29.8 HIP 65292 20.22
2026-10-10 12:00 13:22:49.27 +11:36:44.7 HIP 65292 19.30
2026-10-11 00:00 13:22:56.47 +11:35:59.8 HIP 65292 18.53