C/2021 C3 (Catalina)
メタデータ
| 項目 |
値 |
| Designation |
C/2021 C3 (Catalina) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2021-02-12T10:38:30.753600Z |
| Orbit solution date (soln_date, UTC) |
2024-06-21T13:42:16Z |
| Obs used |
363 |
| NEO |
- |
| M1 |
16.100 |
| K1 |
4.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2021-02-07T11:02:01.017600Z |
| Discovery magnitude (MPC) |
19.15 G |
| Discovery observatory (MPC) |
703 · Catalina Sky Survey |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2021-03-28.0000000 |
| e |
0.96405640 |
| q (au) |
2.276500 |
| a (au) |
63.335351 |
| i (deg) |
122.161615 |
| Ω (om, deg) |
181.919832 |
| ω (w, deg) |
357.151666 |
| M (ma, deg) |
0.085170 |
等級
散乱 + 全体線形
$$
M_a = (17.520 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
17.520 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.650 |
| k |
0.800 |
| 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
残差 (区間線形)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| 開始日 (UTC) |
終了日 (UTC) |
a |
b |
| 2021-02-13 |
2021-06-09 |
-16.5522 |
+5.942 |
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) |
| 2026-02-03 00:00 |
00:27:54.29 |
+45:30:36.6 |
HIP 1978 |
31.65 |
| 2026-02-03 12:00 |
00:28:00.70 |
+45:29:32.1 |
HIP 2285 |
32.31 |
| 2026-02-04 00:00 |
00:28:07.17 |
+45:28:28.3 |
HIP 2285 |
30.89 |
| 2026-02-04 12:00 |
00:28:13.70 |
+45:27:25.3 |
HIP 2285 |
29.51 |
| 2026-02-05 00:00 |
00:28:20.30 |
+45:26:23.0 |
HIP 2285 |
28.14 |
| 2026-02-05 12:00 |
00:28:26.96 |
+45:25:21.6 |
HIP 2285 |
26.81 |
| 2026-02-06 00:00 |
00:28:33.68 |
+45:24:20.8 |
HIP 2285 |
25.51 |
| 2026-02-06 12:00 |
00:28:40.47 |
+45:23:20.9 |
HIP 2285 |
24.25 |
| 2026-02-07 00:00 |
00:28:47.31 |
+45:22:21.7 |
HIP 2285 |
23.04 |
| 2026-02-07 12:00 |
00:28:54.22 |
+45:21:23.3 |
HIP 2285 |
21.89 |
| 2026-02-08 00:00 |
00:29:01.19 |
+45:20:25.7 |
HIP 2285 |
20.80 |
| 2026-02-08 12:00 |
00:29:08.21 |
+45:19:28.8 |
HIP 2285 |
19.78 |
| 2026-02-09 00:00 |
00:29:15.30 |
+45:18:32.7 |
HIP 2285 |
18.86 |
| 2026-02-09 12:00 |
00:29:22.44 |
+45:17:37.4 |
HIP 2285 |
18.03 |
| 2026-02-10 00:00 |
00:29:29.64 |
+45:16:42.8 |
HIP 2341 |
16.91 |
| 2026-02-10 12:00 |
00:29:36.90 |
+45:15:49.1 |
HIP 2341 |
15.74 |
| 2026-02-11 00:00 |
00:29:44.22 |
+45:14:56.1 |
HIP 2341 |
14.66 |
| 2026-02-11 12:00 |
00:29:51.59 |
+45:14:03.8 |
HIP 2341 |
13.69 |
| 2026-02-12 00:00 |
00:29:59.02 |
+45:13:12.4 |
HIP 2341 |
12.84 |
| 2026-02-12 12:00 |
00:30:06.50 |
+45:12:21.7 |
HIP 2341 |
12.16 |
| 2026-02-13 00:00 |
00:30:14.03 |
+45:11:31.8 |
HIP 2341 |
11.66 |
| 2026-02-13 12:00 |
00:30:21.62 |
+45:10:42.7 |
HIP 2341 |
11.37 |
| 2026-02-14 00:00 |
00:30:29.26 |
+45:09:54.4 |
HIP 2341 |
11.32 |
| 2026-02-14 12:00 |
00:30:36.96 |
+45:09:06.8 |
HIP 2341 |
11.49 |
| 2026-02-15 00:00 |
00:30:44.70 |
+45:08:20.1 |
HIP 2341 |
11.89 |
| 2026-02-15 12:00 |
00:30:52.50 |
+45:07:34.1 |
HIP 2341 |
12.49 |
| 2026-02-16 00:00 |
00:31:00.35 |
+45:06:48.8 |
HIP 2341 |
13.27 |
| 2026-02-16 12:00 |
00:31:08.24 |
+45:06:04.4 |
HIP 2341 |
14.20 |
| 2026-02-17 00:00 |
00:31:16.19 |
+45:05:20.7 |
HIP 2341 |
15.24 |
| 2026-02-17 12:00 |
00:31:24.19 |
+45:04:37.9 |
HIP 2341 |
16.38 |
| 2026-02-18 00:00 |
00:31:32.23 |
+45:03:55.7 |
HIP 2341 |
17.61 |
| 2026-02-18 12:00 |
00:31:40.32 |
+45:03:14.4 |
HIP 2341 |
18.90 |
| 2026-02-19 00:00 |
00:31:48.45 |
+45:02:33.8 |
HIP 2341 |
20.24 |
| 2026-02-19 12:00 |
00:31:56.63 |
+45:01:54.1 |
HIP 2600 |
21.40 |
| 2026-02-20 00:00 |
00:32:04.86 |
+45:01:15.1 |
HIP 2600 |
20.10 |
| 2026-02-20 12:00 |
00:32:13.13 |
+45:00:36.8 |
HIP 2600 |
18.84 |
| 2026-02-21 00:00 |
00:32:21.44 |
+44:59:59.4 |
HIP 2600 |
17.65 |
| 2026-02-21 12:00 |
00:32:29.80 |
+44:59:22.7 |
HIP 2600 |
16.53 |
| 2026-02-22 00:00 |
00:32:38.20 |
+44:58:46.7 |
HIP 2600 |
15.51 |
| 2026-02-22 12:00 |
00:32:46.64 |
+44:58:11.6 |
HIP 2600 |
14.61 |
| 2026-02-23 00:00 |
00:32:55.12 |
+44:57:37.2 |
HIP 2600 |
13.85 |
| 2026-02-23 12:00 |
00:33:03.64 |
+44:57:03.6 |
HIP 2600 |
13.25 |
| 2026-02-24 00:00 |
00:33:12.21 |
+44:56:30.7 |
HIP 2600 |
12.85 |