メタデータ
| 項目 |
値 |
| Designation |
C/2018 S2 (TESS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2018-11-05T04:38:14.709120Z |
| Orbit solution date (soln_date, UTC) |
2022-08-25T20:42:05Z |
| Obs used |
803 |
| NEO |
- |
| M1 |
6.700 |
| K1 |
11.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2018-09-23T18:44:41.078400Z |
| Discovery magnitude (MPC) |
18.50 G |
| Discovery observatory (MPC) |
C57 · TESS |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2018-04-11.0000000 |
| e |
0.61491477 |
| q (au) |
5.470619 |
| a (au) |
14.206254 |
| i (deg) |
64.220443 |
| Ω (om, deg) |
85.125919 |
| ω (w, deg) |
290.683496 |
| M (ma, deg) |
356.167772 |
等級
散乱 + 全体線形
$$
M_a = (8.539 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
8.539 |
| n |
6.000 |
| gf |
0.973 |
| gb |
-0.935 |
| k |
0.800 |
| δ90 |
9.920 |
| 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) |
| 2026-09-20 00:00 |
09:58:33.98 |
+63:52:19.8 |
HIP 48819 |
30.59 |
| 2026-09-20 12:00 |
09:58:52.87 |
+63:52:53.5 |
HIP 48819 |
31.68 |
| 2026-09-21 00:00 |
09:59:11.71 |
+63:53:27.9 |
HIP 49291 |
32.07 |
| 2026-09-21 12:00 |
09:59:30.49 |
+63:54:03.0 |
HIP 49291 |
29.94 |
| 2026-09-22 00:00 |
09:59:49.23 |
+63:54:38.7 |
HIP 49291 |
27.82 |
| 2026-09-22 12:00 |
10:00:07.90 |
+63:55:15.2 |
HIP 49291 |
25.71 |
| 2026-09-23 00:00 |
10:00:26.52 |
+63:55:52.4 |
HIP 49291 |
23.60 |
| 2026-09-23 12:00 |
10:00:45.08 |
+63:56:30.2 |
HIP 49291 |
21.50 |
| 2026-09-24 00:00 |
10:01:03.59 |
+63:57:08.8 |
HIP 49291 |
19.40 |
| 2026-09-24 12:00 |
10:01:22.03 |
+63:57:48.0 |
HIP 49291 |
17.32 |
| 2026-09-25 00:00 |
10:01:40.42 |
+63:58:27.9 |
HIP 49291 |
15.24 |
| 2026-09-25 12:00 |
10:01:58.75 |
+63:59:08.5 |
HIP 49291 |
13.18 |
| 2026-09-26 00:00 |
10:02:17.02 |
+63:59:49.8 |
HIP 49291 |
11.14 |
| 2026-09-26 12:00 |
10:02:35.23 |
+64:00:31.8 |
HIP 49291 |
9.13 |
| 2026-09-27 00:00 |
10:02:53.37 |
+64:01:14.5 |
HIP 49291 |
7.18 |
| 2026-09-27 12:00 |
10:03:11.46 |
+64:01:57.9 |
HIP 49291 |
5.35 |
| 2026-09-28 00:00 |
10:03:29.48 |
+64:02:42.0 |
HIP 49291 |
3.80 |
| 2026-09-28 12:00 |
10:03:47.44 |
+64:03:26.7 |
HIP 49291 |
3.01 |
| 2026-09-29 00:00 |
10:04:05.34 |
+64:04:12.2 |
HIP 49291 |
3.52 |
| 2026-09-29 12:00 |
10:04:23.17 |
+64:04:58.3 |
HIP 49291 |
4.94 |
| 2026-09-30 00:00 |
10:04:40.93 |
+64:05:45.2 |
HIP 49291 |
6.71 |
| 2026-09-30 12:00 |
10:04:58.63 |
+64:06:32.7 |
HIP 49291 |
8.62 |
| 2026-10-01 00:00 |
10:05:16.26 |
+64:07:20.9 |
HIP 49291 |
10.59 |
| 2026-10-01 12:00 |
10:05:33.83 |
+64:08:09.9 |
HIP 49291 |
12.59 |
| 2026-10-02 00:00 |
10:05:51.32 |
+64:08:59.5 |
HIP 49291 |
14.60 |
| 2026-10-02 12:00 |
10:06:08.75 |
+64:09:49.8 |
HIP 49456 |
15.09 |
| 2026-10-03 00:00 |
10:06:26.11 |
+64:10:40.8 |
HIP 49456 |
14.62 |
| 2026-10-03 12:00 |
10:06:43.39 |
+64:11:32.5 |
HIP 49456 |
14.42 |
| 2026-10-04 00:00 |
10:07:00.61 |
+64:12:24.9 |
HIP 49456 |
14.50 |
| 2026-10-04 12:00 |
10:07:17.75 |
+64:13:18.0 |
HIP 49456 |
14.85 |
| 2026-10-05 00:00 |
10:07:34.82 |
+64:14:11.8 |
HIP 49456 |
15.45 |
| 2026-10-05 12:00 |
10:07:51.82 |
+64:15:06.3 |
HIP 49716 |
13.84 |
| 2026-10-06 00:00 |
10:08:08.74 |
+64:16:01.5 |
HIP 49716 |
12.11 |
| 2026-10-06 12:00 |
10:08:25.58 |
+64:16:57.4 |
HIP 49716 |
10.49 |
| 2026-10-07 00:00 |
10:08:42.35 |
+64:17:54.0 |
HIP 49716 |
9.03 |
| 2026-10-07 12:00 |
10:08:59.04 |
+64:18:51.3 |
HIP 49716 |
7.83 |
| 2026-10-08 00:00 |
10:09:15.65 |
+64:19:49.3 |
HIP 49716 |
7.02 |
| 2026-10-08 12:00 |
10:09:32.18 |
+64:20:48.0 |
HIP 49716 |
6.73 |
| 2026-10-09 00:00 |
10:09:48.63 |
+64:21:47.3 |
HIP 49716 |
7.02 |
| 2026-10-09 12:00 |
10:10:05.00 |
+64:22:47.4 |
HIP 49716 |
7.84 |
| 2026-10-10 00:00 |
10:10:21.29 |
+64:23:48.2 |
HIP 49716 |
9.03 |
| 2026-10-10 12:00 |
10:10:37.50 |
+64:24:49.6 |
HIP 49904 |
9.14 |
| 2026-10-11 00:00 |
10:10:53.62 |
+64:25:51.7 |
HIP 49904 |
7.40 |