メタデータ
| 項目 |
値 |
| Designation |
C/2020 T2 (Palomar) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2021-07-11T03:28:26.996160Z |
| Orbit solution date (soln_date, UTC) |
2024-07-30T14:57:24Z |
| Obs used |
2755 |
| NEO |
- |
| M1 |
9.500 |
| K1 |
10.250 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2020-10-07T12:21:14.400000Z |
| Discovery magnitude (MPC) |
19.33 r |
| Discovery observatory (MPC) |
I41 · Palomar Mountain–ZTF |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2021-05-15.0000000 |
| e |
0.99342864 |
| q (au) |
2.054696 |
| a (au) |
312.674502 |
| i (deg) |
27.872916 |
| Ω (om, deg) |
83.048376 |
| ω (w, deg) |
150.381486 |
| M (ma, deg) |
359.989813 |
等級
散乱 + 全体線形
$$
M_a = (7.304 + 5.380\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
7.304 |
| n |
5.380 |
| gf |
1.000 |
| gb |
-0.950 |
| k |
0.999 |
| 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 |
| 2019-12-11 |
2021-07-11 |
+4.3368 |
-2.066 |
| 2021-07-11 |
2022-09-21 |
+1.1155 |
-2.046 |
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 |
01:36:05.97 |
-20:28:23.7 |
HIP 7461 |
2.72 |
| 2026-09-20 12:00 |
01:35:59.55 |
-20:29:17.8 |
HIP 7461 |
2.68 |
| 2026-09-21 00:00 |
01:35:53.10 |
-20:30:11.6 |
HIP 7461 |
3.62 |
| 2026-09-21 12:00 |
01:35:46.62 |
-20:31:05.0 |
HIP 7461 |
5.03 |
| 2026-09-22 00:00 |
01:35:40.10 |
-20:31:58.1 |
HIP 7461 |
6.62 |
| 2026-09-22 12:00 |
01:35:33.55 |
-20:32:50.8 |
HIP 7461 |
8.29 |
| 2026-09-23 00:00 |
01:35:26.97 |
-20:33:43.2 |
HIP 7461 |
9.99 |
| 2026-09-23 12:00 |
01:35:20.35 |
-20:34:35.2 |
HIP 7461 |
11.72 |
| 2026-09-24 00:00 |
01:35:13.71 |
-20:35:26.8 |
HIP 7461 |
13.47 |
| 2026-09-24 12:00 |
01:35:07.04 |
-20:36:18.1 |
HIP 7461 |
15.22 |
| 2026-09-25 00:00 |
01:35:00.33 |
-20:37:08.9 |
HIP 7461 |
16.99 |
| 2026-09-25 12:00 |
01:34:53.60 |
-20:37:59.4 |
HIP 7461 |
18.76 |
| 2026-09-26 00:00 |
01:34:46.84 |
-20:38:49.5 |
HIP 7461 |
20.54 |
| 2026-09-26 12:00 |
01:34:40.06 |
-20:39:39.2 |
HIP 7461 |
22.32 |
| 2026-09-27 00:00 |
01:34:33.24 |
-20:40:28.5 |
HIP 7284 |
23.63 |
| 2026-09-27 12:00 |
01:34:26.40 |
-20:41:17.4 |
HIP 7284 |
22.27 |
| 2026-09-28 00:00 |
01:34:19.54 |
-20:42:05.9 |
HIP 7284 |
20.97 |
| 2026-09-28 12:00 |
01:34:12.65 |
-20:42:53.9 |
HIP 7284 |
19.75 |
| 2026-09-29 00:00 |
01:34:05.74 |
-20:43:41.6 |
HIP 7284 |
18.64 |
| 2026-09-29 12:00 |
01:33:58.80 |
-20:44:28.8 |
HIP 7284 |
17.64 |
| 2026-09-30 00:00 |
01:33:51.84 |
-20:45:15.6 |
HIP 7284 |
16.79 |
| 2026-09-30 12:00 |
01:33:44.86 |
-20:46:01.9 |
HIP 7284 |
16.10 |
| 2026-10-01 00:00 |
01:33:37.85 |
-20:46:47.9 |
HIP 7284 |
15.60 |
| 2026-10-01 12:00 |
01:33:30.83 |
-20:47:33.3 |
HIP 7284 |
15.31 |
| 2026-10-02 00:00 |
01:33:23.78 |
-20:48:18.3 |
HIP 7284 |
15.24 |
| 2026-10-02 12:00 |
01:33:16.71 |
-20:49:02.9 |
HIP 7284 |
15.38 |
| 2026-10-03 00:00 |
01:33:09.63 |
-20:49:47.0 |
HIP 7159 |
14.53 |
| 2026-10-03 12:00 |
01:33:02.53 |
-20:50:30.6 |
HIP 7159 |
13.57 |
| 2026-10-04 00:00 |
01:32:55.41 |
-20:51:13.8 |
HIP 7159 |
12.78 |
| 2026-10-04 12:00 |
01:32:48.27 |
-20:51:56.5 |
HIP 7159 |
12.20 |
| 2026-10-05 00:00 |
01:32:41.11 |
-20:52:38.7 |
HIP 7159 |
11.87 |
| 2026-10-05 12:00 |
01:32:33.95 |
-20:53:20.4 |
HIP 7159 |
11.80 |
| 2026-10-06 00:00 |
01:32:26.76 |
-20:54:01.6 |
HIP 7159 |
12.00 |
| 2026-10-06 12:00 |
01:32:19.56 |
-20:54:42.4 |
HIP 7159 |
12.46 |
| 2026-10-07 00:00 |
01:32:12.35 |
-20:55:22.6 |
HIP 7159 |
13.14 |
| 2026-10-07 12:00 |
01:32:05.13 |
-20:56:02.3 |
HIP 7159 |
14.02 |
| 2026-10-08 00:00 |
01:31:57.89 |
-20:56:41.6 |
HIP 7159 |
15.06 |
| 2026-10-08 12:00 |
01:31:50.64 |
-20:57:20.3 |
HIP 7159 |
16.23 |
| 2026-10-09 00:00 |
01:31:43.39 |
-20:57:58.4 |
HIP 7159 |
17.50 |
| 2026-10-09 12:00 |
01:31:36.12 |
-20:58:36.1 |
HIP 7159 |
18.85 |
| 2026-10-10 00:00 |
01:31:28.85 |
-20:59:13.2 |
HIP 7159 |
20.27 |
| 2026-10-10 12:00 |
01:31:21.56 |
-20:59:49.8 |
HIP 7159 |
21.74 |
| 2026-10-11 00:00 |
01:31:14.27 |
-21:00:25.9 |
HIP 7159 |
23.25 |