C/1917 F1 (Mellish)
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) |
| 2026-02-03 00:00 |
02:51:11.36 |
-11:07:32.4 |
HIP 13249 |
26.42 |
| 2026-02-03 12:00 |
02:51:11.30 |
-11:07:13.5 |
HIP 13249 |
26.71 |
| 2026-02-04 00:00 |
02:51:11.27 |
-11:06:54.4 |
HIP 13249 |
27.00 |
| 2026-02-04 12:00 |
02:51:11.27 |
-11:06:35.2 |
HIP 13249 |
27.30 |
| 2026-02-05 00:00 |
02:51:11.28 |
-11:06:16.0 |
HIP 13249 |
27.60 |
| 2026-02-05 12:00 |
02:51:11.32 |
-11:05:56.7 |
HIP 13249 |
27.90 |
| 2026-02-06 00:00 |
02:51:11.38 |
-11:05:37.3 |
HIP 13249 |
28.21 |
| 2026-02-06 12:00 |
02:51:11.47 |
-11:05:17.8 |
HIP 13249 |
28.52 |
| 2026-02-07 00:00 |
02:51:11.58 |
-11:04:58.2 |
HIP 13249 |
28.84 |
| 2026-02-07 12:00 |
02:51:11.71 |
-11:04:38.5 |
HIP 13249 |
29.16 |
| 2026-02-08 00:00 |
02:51:11.86 |
-11:04:18.8 |
HIP 13249 |
29.48 |
| 2026-02-08 12:00 |
02:51:12.04 |
-11:03:59.0 |
HIP 13249 |
29.81 |
| 2026-02-09 00:00 |
02:51:12.24 |
-11:03:39.1 |
HIP 13249 |
30.14 |
| 2026-02-09 12:00 |
02:51:12.46 |
-11:03:19.1 |
HIP 13249 |
30.47 |
| 2026-02-10 00:00 |
02:51:12.71 |
-11:02:59.1 |
HIP 13249 |
30.80 |
| 2026-02-10 12:00 |
02:51:12.98 |
-11:02:39.0 |
HIP 13249 |
31.14 |
| 2026-02-11 00:00 |
02:51:13.27 |
-11:02:18.8 |
HIP 13249 |
31.48 |
| 2026-02-11 12:00 |
02:51:13.59 |
-11:01:58.6 |
HIP 13249 |
31.83 |
| 2026-02-12 00:00 |
02:51:13.93 |
-11:01:38.3 |
HIP 13249 |
32.17 |
| 2026-02-12 12:00 |
02:51:14.29 |
-11:01:17.9 |
HIP 13249 |
32.52 |
| 2026-02-13 00:00 |
02:51:14.67 |
-11:00:57.5 |
HIP 13249 |
32.88 |
| 2026-02-13 12:00 |
02:51:15.08 |
-11:00:37.0 |
HIP 13249 |
33.23 |
| 2026-02-14 00:00 |
02:51:15.51 |
-11:00:16.5 |
HIP 13249 |
33.59 |
| 2026-02-14 12:00 |
02:51:15.96 |
-10:59:55.9 |
HIP 13249 |
33.95 |
| 2026-02-15 00:00 |
02:51:16.44 |
-10:59:35.2 |
HIP 13249 |
34.31 |
| 2026-02-15 12:00 |
02:51:16.93 |
-10:59:14.5 |
HIP 13249 |
34.68 |
| 2026-02-16 00:00 |
02:51:17.45 |
-10:58:53.7 |
HIP 13249 |
35.05 |
| 2026-02-16 12:00 |
02:51:18.00 |
-10:58:32.9 |
HIP 13249 |
35.42 |
| 2026-02-17 00:00 |
02:51:18.56 |
-10:58:12.0 |
HIP 13249 |
35.80 |
| 2026-02-17 12:00 |
02:51:19.15 |
-10:57:51.1 |
HIP 13249 |
36.17 |
| 2026-02-18 00:00 |
02:51:19.76 |
-10:57:30.1 |
HIP 13249 |
36.55 |
| 2026-02-18 12:00 |
02:51:20.39 |
-10:57:09.1 |
HIP 13249 |
36.93 |
| 2026-02-19 00:00 |
02:51:21.05 |
-10:56:48.0 |
HIP 13249 |
37.32 |
| 2026-02-19 12:00 |
02:51:21.73 |
-10:56:26.9 |
HIP 13249 |
37.70 |
| 2026-02-20 00:00 |
02:51:22.42 |
-10:56:05.8 |
HIP 13168 |
37.93 |
| 2026-02-20 12:00 |
02:51:23.15 |
-10:55:44.6 |
HIP 13168 |
37.86 |
| 2026-02-21 00:00 |
02:51:23.89 |
-10:55:23.4 |
HIP 13168 |
37.80 |
| 2026-02-21 12:00 |
02:51:24.65 |
-10:55:02.1 |
HIP 13168 |
37.74 |
| 2026-02-22 00:00 |
02:51:25.44 |
-10:54:40.9 |
HIP 13168 |
37.69 |
| 2026-02-22 12:00 |
02:51:26.25 |
-10:54:19.5 |
HIP 13168 |
37.65 |
| 2026-02-23 00:00 |
02:51:27.08 |
-10:53:58.2 |
HIP 13168 |
37.62 |
| 2026-02-23 12:00 |
02:51:27.93 |
-10:53:36.8 |
HIP 13168 |
37.60 |
| 2026-02-24 00:00 |
02:51:28.80 |
-10:53:15.4 |
HIP 13168 |
37.59 |