メタデータ
| 項目 |
値 |
| Designation |
C/2017 S7 (Lemmon) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2017-05-27T21:16:49.696320Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:36Z |
| Obs used |
157 |
| NEO |
- |
| M1 |
6.700 |
| K1 |
10.000 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2017-11-16.0000000 |
| e |
1.00249982 |
| q (au) |
7.614408 |
| a (au) |
-3045.987574 |
| i (deg) |
124.224743 |
| Ω (om, deg) |
262.788416 |
| ω (w, deg) |
187.747383 |
| M (ma, deg) |
0.001009 |
等級
散乱 + 全体線形
$$
M_a = (1.282 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
1.282 |
| n |
6.000 |
| gf |
0.998 |
| gb |
-0.721 |
| k |
1.000 |
| 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
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
23:46:43.17 |
-59:08:17.7 |
HIP 117152 |
13.19 |
| 2026-05-12 12:00 |
23:46:47.09 |
-59:09:13.9 |
HIP 117152 |
13.56 |
| 2026-05-13 00:00 |
23:46:50.95 |
-59:10:10.6 |
HIP 117152 |
13.99 |
| 2026-05-13 12:00 |
23:46:54.73 |
-59:11:07.9 |
HIP 117152 |
14.48 |
| 2026-05-14 00:00 |
23:46:58.44 |
-59:12:05.6 |
HIP 117152 |
15.02 |
| 2026-05-14 12:00 |
23:47:02.08 |
-59:13:03.9 |
HIP 117152 |
15.61 |
| 2026-05-15 00:00 |
23:47:05.65 |
-59:14:02.7 |
HIP 117431 |
16.01 |
| 2026-05-15 12:00 |
23:47:09.14 |
-59:15:02.0 |
HIP 117431 |
16.36 |
| 2026-05-16 00:00 |
23:47:12.56 |
-59:16:01.8 |
HIP 117431 |
16.78 |
| 2026-05-16 12:00 |
23:47:15.91 |
-59:17:02.1 |
HIP 117431 |
17.28 |
| 2026-05-17 00:00 |
23:47:19.18 |
-59:18:02.9 |
HIP 117431 |
17.84 |
| 2026-05-17 12:00 |
23:47:22.37 |
-59:19:04.2 |
HIP 117431 |
18.46 |
| 2026-05-18 00:00 |
23:47:25.49 |
-59:20:06.0 |
HIP 117431 |
19.14 |
| 2026-05-18 12:00 |
23:47:28.54 |
-59:21:08.2 |
HIP 117147 |
19.55 |
| 2026-05-19 00:00 |
23:47:31.50 |
-59:22:10.9 |
HIP 117147 |
19.74 |
| 2026-05-19 12:00 |
23:47:34.39 |
-59:23:14.1 |
HIP 117147 |
19.97 |
| 2026-05-20 00:00 |
23:47:37.21 |
-59:24:17.8 |
HIP 117147 |
20.25 |
| 2026-05-20 12:00 |
23:47:39.94 |
-59:25:22.0 |
HIP 117147 |
20.58 |
| 2026-05-21 00:00 |
23:47:42.60 |
-59:26:26.6 |
HIP 117147 |
20.95 |
| 2026-05-21 12:00 |
23:47:45.17 |
-59:27:31.6 |
HIP 117147 |
21.36 |
| 2026-05-22 00:00 |
23:47:47.67 |
-59:28:37.1 |
HIP 117147 |
21.82 |
| 2026-05-22 12:00 |
23:47:50.09 |
-59:29:43.1 |
HIP 117147 |
22.32 |
| 2026-05-23 00:00 |
23:47:52.42 |
-59:30:49.5 |
HIP 117147 |
22.86 |
| 2026-05-23 12:00 |
23:47:54.68 |
-59:31:56.3 |
HIP 117147 |
23.43 |
| 2026-05-24 00:00 |
23:47:56.85 |
-59:33:03.6 |
HIP 117147 |
24.03 |
| 2026-05-24 12:00 |
23:47:58.95 |
-59:34:11.3 |
HIP 117275 |
23.40 |
| 2026-05-25 00:00 |
23:48:00.96 |
-59:35:19.5 |
HIP 117275 |
22.44 |
| 2026-05-25 12:00 |
23:48:02.88 |
-59:36:28.0 |
HIP 117275 |
21.49 |
| 2026-05-26 00:00 |
23:48:04.73 |
-59:37:37.0 |
HIP 117275 |
20.56 |
| 2026-05-26 12:00 |
23:48:06.49 |
-59:38:46.4 |
HIP 117275 |
19.64 |
| 2026-05-27 00:00 |
23:48:08.17 |
-59:39:56.2 |
HIP 117275 |
18.73 |
| 2026-05-27 12:00 |
23:48:09.77 |
-59:41:06.4 |
HIP 117275 |
17.85 |
| 2026-05-28 00:00 |
23:48:11.28 |
-59:42:17.0 |
HIP 117275 |
16.99 |
| 2026-05-28 12:00 |
23:48:12.70 |
-59:43:28.0 |
HIP 117275 |
16.17 |
| 2026-05-29 00:00 |
23:48:14.04 |
-59:44:39.4 |
HIP 117275 |
15.38 |
| 2026-05-29 12:00 |
23:48:15.30 |
-59:45:51.2 |
HIP 117275 |
14.63 |
| 2026-05-30 00:00 |
23:48:16.47 |
-59:47:03.3 |
HIP 117275 |
13.93 |
| 2026-05-30 12:00 |
23:48:17.55 |
-59:48:15.9 |
HIP 117275 |
13.30 |
| 2026-05-31 00:00 |
23:48:18.55 |
-59:49:28.8 |
HIP 117275 |
12.74 |
| 2026-05-31 12:00 |
23:48:19.46 |
-59:50:42.1 |
HIP 117275 |
12.26 |
| 2026-06-01 00:00 |
23:48:20.28 |
-59:51:55.7 |
HIP 117275 |
11.88 |
| 2026-06-01 12:00 |
23:48:21.01 |
-59:53:09.7 |
HIP 117275 |
11.61 |
| 2026-06-02 00:00 |
23:48:21.66 |
-59:54:24.1 |
HIP 117275 |
11.45 |