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) |
| 2026-07-29 00:00 |
03:01:30.94 |
-10:17:07.3 |
HIP 14050 |
17.51 |
| 2026-07-29 12:00 |
03:01:31.50 |
-10:17:23.0 |
HIP 14050 |
17.81 |
| 2026-07-30 00:00 |
03:01:32.05 |
-10:17:38.8 |
HIP 14050 |
18.10 |
| 2026-07-30 12:00 |
03:01:32.57 |
-10:17:54.8 |
HIP 14151 |
18.33 |
| 2026-07-31 00:00 |
03:01:33.07 |
-10:18:10.8 |
HIP 14151 |
18.05 |
| 2026-07-31 12:00 |
03:01:33.55 |
-10:18:27.0 |
HIP 14151 |
17.78 |
| 2026-08-01 00:00 |
03:01:34.01 |
-10:18:43.3 |
HIP 14151 |
17.51 |
| 2026-08-01 12:00 |
03:01:34.45 |
-10:18:59.7 |
HIP 14151 |
17.25 |
| 2026-08-02 00:00 |
03:01:34.86 |
-10:19:16.3 |
HIP 14151 |
16.99 |
| 2026-08-02 12:00 |
03:01:35.26 |
-10:19:32.9 |
HIP 14151 |
16.73 |
| 2026-08-03 00:00 |
03:01:35.63 |
-10:19:49.7 |
HIP 14151 |
16.48 |
| 2026-08-03 12:00 |
03:01:35.98 |
-10:20:06.5 |
HIP 14151 |
16.23 |
| 2026-08-04 00:00 |
03:01:36.31 |
-10:20:23.5 |
HIP 14151 |
15.99 |
| 2026-08-04 12:00 |
03:01:36.61 |
-10:20:40.6 |
HIP 14151 |
15.75 |
| 2026-08-05 00:00 |
03:01:36.90 |
-10:20:57.8 |
HIP 14151 |
15.52 |
| 2026-08-05 12:00 |
03:01:37.16 |
-10:21:15.1 |
HIP 14151 |
15.29 |
| 2026-08-06 00:00 |
03:01:37.40 |
-10:21:32.5 |
HIP 14151 |
15.07 |
| 2026-08-06 12:00 |
03:01:37.62 |
-10:21:50.0 |
HIP 14151 |
14.85 |
| 2026-08-07 00:00 |
03:01:37.81 |
-10:22:07.7 |
HIP 14151 |
14.64 |
| 2026-08-07 12:00 |
03:01:37.99 |
-10:22:25.4 |
HIP 14151 |
14.44 |
| 2026-08-08 00:00 |
03:01:38.14 |
-10:22:43.2 |
HIP 14151 |
14.24 |
| 2026-08-08 12:00 |
03:01:38.27 |
-10:23:01.1 |
HIP 14151 |
14.05 |
| 2026-08-09 00:00 |
03:01:38.37 |
-10:23:19.2 |
HIP 14151 |
13.87 |
| 2026-08-09 12:00 |
03:01:38.46 |
-10:23:37.3 |
HIP 14151 |
13.69 |
| 2026-08-10 00:00 |
03:01:38.52 |
-10:23:55.5 |
HIP 14151 |
13.53 |
| 2026-08-10 12:00 |
03:01:38.56 |
-10:24:13.8 |
HIP 14151 |
13.37 |
| 2026-08-11 00:00 |
03:01:38.58 |
-10:24:32.2 |
HIP 14151 |
13.23 |
| 2026-08-11 12:00 |
03:01:38.57 |
-10:24:50.7 |
HIP 14151 |
13.09 |
| 2026-08-12 00:00 |
03:01:38.55 |
-10:25:09.3 |
HIP 14151 |
12.96 |
| 2026-08-12 12:00 |
03:01:38.50 |
-10:25:28.0 |
HIP 14151 |
12.85 |
| 2026-08-13 00:00 |
03:01:38.42 |
-10:25:46.8 |
HIP 14151 |
12.74 |
| 2026-08-13 12:00 |
03:01:38.33 |
-10:26:05.6 |
HIP 14151 |
12.65 |
| 2026-08-14 00:00 |
03:01:38.21 |
-10:26:24.6 |
HIP 14151 |
12.57 |
| 2026-08-14 12:00 |
03:01:38.07 |
-10:26:43.6 |
HIP 14151 |
12.50 |
| 2026-08-15 00:00 |
03:01:37.91 |
-10:27:02.7 |
HIP 14151 |
12.44 |
| 2026-08-15 12:00 |
03:01:37.72 |
-10:27:21.9 |
HIP 14151 |
12.40 |
| 2026-08-16 00:00 |
03:01:37.52 |
-10:27:41.1 |
HIP 14151 |
12.37 |
| 2026-08-16 12:00 |
03:01:37.29 |
-10:28:00.5 |
HIP 14151 |
12.35 |
| 2026-08-17 00:00 |
03:01:37.03 |
-10:28:19.9 |
HIP 14151 |
12.35 |
| 2026-08-17 12:00 |
03:01:36.76 |
-10:28:39.4 |
HIP 14151 |
12.36 |
| 2026-08-18 00:00 |
03:01:36.46 |
-10:28:59.0 |
HIP 14151 |
12.39 |
| 2026-08-18 12:00 |
03:01:36.14 |
-10:29:18.6 |
HIP 14151 |
12.43 |
| 2026-08-19 00:00 |
03:01:35.80 |
-10:29:38.4 |
HIP 14151 |
12.48 |