メタデータ
| 項目 |
値 |
| Designation |
C/1917 F1 (Mellish) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1917-04-11T04:12:43.113600Z |
| Orbit solution date (soln_date, UTC) |
2025-09-09T12:42:30Z |
| Obs used |
12 |
| NEO |
Yes |
| M1 |
10.900 |
| K1 |
15.750 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
1917-04-17.0000000 |
| e |
0.99302944 |
| q (au) |
0.190197 |
| a (au) |
27.285690 |
| i (deg) |
32.686283 |
| Ω (om, deg) |
88.675684 |
| ω (w, deg) |
121.313996 |
| M (ma, deg) |
0.040277 |
等級
散乱 + 全体線形
$$
M_a = (9.401 + 5.430\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
9.401 |
| n |
5.430 |
| gf |
0.800 |
| gb |
-1.000 |
| k |
1.000 |
| 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
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
03:00:28.82 |
-10:51:59.8 |
HIP 13919 |
17.25 |
| 2026-09-20 12:00 |
03:00:27.12 |
-10:52:20.8 |
HIP 13919 |
16.86 |
| 2026-09-21 00:00 |
03:00:25.39 |
-10:52:41.9 |
HIP 13919 |
16.48 |
| 2026-09-21 12:00 |
03:00:23.65 |
-10:53:02.9 |
HIP 13919 |
16.10 |
| 2026-09-22 00:00 |
03:00:21.88 |
-10:53:23.8 |
HIP 13919 |
15.73 |
| 2026-09-22 12:00 |
03:00:20.11 |
-10:53:44.7 |
HIP 13919 |
15.36 |
| 2026-09-23 00:00 |
03:00:18.31 |
-10:54:05.6 |
HIP 13919 |
15.01 |
| 2026-09-23 12:00 |
03:00:16.49 |
-10:54:26.5 |
HIP 13919 |
14.66 |
| 2026-09-24 00:00 |
03:00:14.66 |
-10:54:47.2 |
HIP 13919 |
14.32 |
| 2026-09-24 12:00 |
03:00:12.81 |
-10:55:08.0 |
HIP 13919 |
13.99 |
| 2026-09-25 00:00 |
03:00:10.94 |
-10:55:28.7 |
HIP 13919 |
13.68 |
| 2026-09-25 12:00 |
03:00:09.06 |
-10:55:49.3 |
HIP 13919 |
13.37 |
| 2026-09-26 00:00 |
03:00:07.16 |
-10:56:09.9 |
HIP 13919 |
13.09 |
| 2026-09-26 12:00 |
03:00:05.24 |
-10:56:30.5 |
HIP 13919 |
12.81 |
| 2026-09-27 00:00 |
03:00:03.31 |
-10:56:51.0 |
HIP 13919 |
12.56 |
| 2026-09-27 12:00 |
03:00:01.35 |
-10:57:11.4 |
HIP 13919 |
12.32 |
| 2026-09-28 00:00 |
02:59:59.39 |
-10:57:31.8 |
HIP 13919 |
12.10 |
| 2026-09-28 12:00 |
02:59:57.40 |
-10:57:52.2 |
HIP 13919 |
11.90 |
| 2026-09-29 00:00 |
02:59:55.40 |
-10:58:12.4 |
HIP 13919 |
11.73 |
| 2026-09-29 12:00 |
02:59:53.39 |
-10:58:32.7 |
HIP 13919 |
11.58 |
| 2026-09-30 00:00 |
02:59:51.35 |
-10:58:52.8 |
HIP 13919 |
11.46 |
| 2026-09-30 12:00 |
02:59:49.31 |
-10:59:12.9 |
HIP 13919 |
11.37 |
| 2026-10-01 00:00 |
02:59:47.24 |
-10:59:32.9 |
HIP 13919 |
11.30 |
| 2026-10-01 12:00 |
02:59:45.16 |
-10:59:52.9 |
HIP 13919 |
11.26 |
| 2026-10-02 00:00 |
02:59:43.07 |
-11:00:12.7 |
HIP 13919 |
11.25 |
| 2026-10-02 12:00 |
02:59:40.96 |
-11:00:32.6 |
HIP 13919 |
11.28 |
| 2026-10-03 00:00 |
02:59:38.84 |
-11:00:52.3 |
HIP 13896 |
11.32 |
| 2026-10-03 12:00 |
02:59:36.70 |
-11:01:12.0 |
HIP 13896 |
10.95 |
| 2026-10-04 00:00 |
02:59:34.54 |
-11:01:31.6 |
HIP 13896 |
10.60 |
| 2026-10-04 12:00 |
02:59:32.37 |
-11:01:51.1 |
HIP 13896 |
10.28 |
| 2026-10-05 00:00 |
02:59:30.19 |
-11:02:10.5 |
HIP 13896 |
9.97 |
| 2026-10-05 12:00 |
02:59:27.99 |
-11:02:29.9 |
HIP 13896 |
9.70 |
| 2026-10-06 00:00 |
02:59:25.78 |
-11:02:49.2 |
HIP 13896 |
9.45 |
| 2026-10-06 12:00 |
02:59:23.55 |
-11:03:08.4 |
HIP 13896 |
9.24 |
| 2026-10-07 00:00 |
02:59:21.31 |
-11:03:27.5 |
HIP 13896 |
9.06 |
| 2026-10-07 12:00 |
02:59:19.06 |
-11:03:46.5 |
HIP 13896 |
8.92 |
| 2026-10-08 00:00 |
02:59:16.79 |
-11:04:05.4 |
HIP 13896 |
8.82 |
| 2026-10-08 12:00 |
02:59:14.51 |
-11:04:24.3 |
HIP 13896 |
8.77 |
| 2026-10-09 00:00 |
02:59:12.21 |
-11:04:43.0 |
HIP 13896 |
8.76 |
| 2026-10-09 12:00 |
02:59:09.91 |
-11:05:01.7 |
HIP 13896 |
8.79 |
| 2026-10-10 00:00 |
02:59:07.59 |
-11:05:20.2 |
HIP 13896 |
8.87 |
| 2026-10-10 12:00 |
02:59:05.25 |
-11:05:38.7 |
HIP 13896 |
8.99 |
| 2026-10-11 00:00 |
02:59:02.91 |
-11:05:57.0 |
HIP 13896 |
9.16 |