メタデータ
| 項目 |
値 |
| Designation |
C/2021 S4 (Tsuchinshan) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2024-01-02T08:37:33.602880Z |
| Orbit solution date (soln_date, UTC) |
2026-09-21T07:12:11Z |
| Obs used |
1163 |
| NEO |
- |
| M1 |
6.400 |
| K1 |
9.250 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2021-09-29T18:31:15.744000Z |
| Discovery magnitude (MPC) |
20.50 R |
| Discovery observatory (MPC) |
D29 · Purple Mountain Observatory, XuYi Station |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2023-10-27.0000000 |
| e |
0.95932849 |
| q (au) |
6.689313 |
| a (au) |
164.471719 |
| i (deg) |
17.478931 |
| Ω (om, deg) |
5.490778 |
| ω (w, deg) |
72.871385 |
| M (ma, deg) |
359.968525 |
等級
散乱 + 全体線形
$$
M_a = (0.603 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
0.603 |
| n |
6.000 |
| gf |
0.913 |
| gb |
-0.916 |
| k |
1.000 |
| δ90 |
8.803 |
| 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 |
| 2021-09-08 |
2024-01-01 |
+9.2478 |
-7.921 |
| 2024-01-02 |
2026-02-23 |
+17.3082 |
-14.299 |
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 |
10:10:10.54 |
+23:02:48.2 |
HIP 49700 |
32.70 |
| 2026-09-20 12:00 |
10:10:25.24 |
+23:01:32.2 |
HIP 49700 |
35.80 |
| 2026-09-21 00:00 |
10:10:39.91 |
+23:00:16.5 |
HIP 50048 |
34.42 |
| 2026-09-21 12:00 |
10:10:54.52 |
+22:59:01.3 |
HIP 50048 |
30.86 |
| 2026-09-22 00:00 |
10:11:09.10 |
+22:57:46.4 |
HIP 50048 |
27.32 |
| 2026-09-22 12:00 |
10:11:23.62 |
+22:56:32.0 |
HIP 50048 |
23.80 |
| 2026-09-23 00:00 |
10:11:38.11 |
+22:55:17.9 |
HIP 50048 |
20.30 |
| 2026-09-23 12:00 |
10:11:52.54 |
+22:54:04.3 |
HIP 50048 |
16.84 |
| 2026-09-24 00:00 |
10:12:06.93 |
+22:52:51.0 |
HIP 50048 |
13.44 |
| 2026-09-24 12:00 |
10:12:21.26 |
+22:51:38.2 |
HIP 50048 |
10.13 |
| 2026-09-25 00:00 |
10:12:35.55 |
+22:50:25.8 |
HIP 50048 |
7.03 |
| 2026-09-25 12:00 |
10:12:49.80 |
+22:49:13.7 |
HIP 50048 |
4.58 |
| 2026-09-26 00:00 |
10:13:03.99 |
+22:48:02.2 |
HIP 50048 |
4.10 |
| 2026-09-26 12:00 |
10:13:18.13 |
+22:46:51.0 |
HIP 50048 |
6.06 |
| 2026-09-27 00:00 |
10:13:32.22 |
+22:45:40.2 |
HIP 50048 |
8.97 |
| 2026-09-27 12:00 |
10:13:46.27 |
+22:44:29.9 |
HIP 50048 |
12.16 |
| 2026-09-28 00:00 |
10:14:00.26 |
+22:43:20.0 |
HIP 50048 |
15.44 |
| 2026-09-28 12:00 |
10:14:14.20 |
+22:42:10.6 |
HIP 50130 |
15.05 |
| 2026-09-29 00:00 |
10:14:28.09 |
+22:41:01.5 |
HIP 50130 |
14.92 |
| 2026-09-29 12:00 |
10:14:41.92 |
+22:39:52.9 |
HIP 50130 |
15.54 |
| 2026-09-30 00:00 |
10:14:55.70 |
+22:38:44.8 |
HIP 50130 |
16.84 |
| 2026-09-30 12:00 |
10:15:09.43 |
+22:37:37.1 |
HIP 50130 |
18.66 |
| 2026-10-01 00:00 |
10:15:23.11 |
+22:36:29.8 |
HIP 50130 |
20.86 |
| 2026-10-01 12:00 |
10:15:36.73 |
+22:35:23.0 |
HIP 50130 |
23.33 |
| 2026-10-02 00:00 |
10:15:50.30 |
+22:34:16.6 |
HIP 50130 |
25.98 |
| 2026-10-02 12:00 |
10:16:03.81 |
+22:33:10.7 |
HIP 50130 |
28.76 |
| 2026-10-03 00:00 |
10:16:17.26 |
+22:32:05.2 |
HIP 50130 |
31.64 |
| 2026-10-03 12:00 |
10:16:30.66 |
+22:31:00.2 |
HIP 50130 |
34.57 |
| 2026-10-04 00:00 |
10:16:44.00 |
+22:29:55.6 |
HIP 50364 |
35.35 |
| 2026-10-04 12:00 |
10:16:57.29 |
+22:28:51.6 |
HIP 50444 |
33.89 |
| 2026-10-05 00:00 |
10:17:10.51 |
+22:27:47.9 |
HIP 50444 |
31.73 |
| 2026-10-05 12:00 |
10:17:23.68 |
+22:26:44.8 |
HIP 50444 |
29.77 |
| 2026-10-06 00:00 |
10:17:36.79 |
+22:25:42.1 |
HIP 50444 |
28.06 |
| 2026-10-06 12:00 |
10:17:49.83 |
+22:24:39.9 |
HIP 50557 |
25.83 |
| 2026-10-07 00:00 |
10:18:02.82 |
+22:23:38.2 |
HIP 50557 |
23.20 |
| 2026-10-07 12:00 |
10:18:15.74 |
+22:22:37.0 |
HIP 50557 |
20.72 |
| 2026-10-08 00:00 |
10:18:28.61 |
+22:21:36.3 |
HIP 50557 |
18.46 |
| 2026-10-08 12:00 |
10:18:41.41 |
+22:20:36.0 |
HIP 50557 |
16.50 |
| 2026-10-09 00:00 |
10:18:54.15 |
+22:19:36.3 |
HIP 50557 |
14.94 |
| 2026-10-09 12:00 |
10:19:06.82 |
+22:18:37.0 |
HIP 50557 |
13.92 |
| 2026-10-10 00:00 |
10:19:19.43 |
+22:17:38.2 |
HIP 50557 |
13.53 |
| 2026-10-10 12:00 |
10:19:31.98 |
+22:16:40.0 |
HIP 50557 |
13.82 |
| 2026-10-11 00:00 |
10:19:44.46 |
+22:15:42.2 |
HIP 50557 |
14.75 |