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 |
1.000 |
| gb |
-0.505 |
| 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) |
| 2026-07-29 00:00 |
23:38:49.76 |
-62:30:01.0 |
HIP 116509 |
22.05 |
| 2026-07-29 12:00 |
23:38:39.01 |
-62:31:15.7 |
HIP 116509 |
20.29 |
| 2026-07-30 00:00 |
23:38:28.18 |
-62:32:30.0 |
HIP 116509 |
18.53 |
| 2026-07-30 12:00 |
23:38:17.25 |
-62:33:43.9 |
HIP 116509 |
16.77 |
| 2026-07-31 00:00 |
23:38:06.23 |
-62:34:57.3 |
HIP 116509 |
15.01 |
| 2026-07-31 12:00 |
23:37:55.13 |
-62:36:10.4 |
HIP 116509 |
13.24 |
| 2026-08-01 00:00 |
23:37:43.94 |
-62:37:23.1 |
HIP 116509 |
11.48 |
| 2026-08-01 12:00 |
23:37:32.66 |
-62:38:35.3 |
HIP 116509 |
9.71 |
| 2026-08-02 00:00 |
23:37:21.30 |
-62:39:47.1 |
HIP 116509 |
7.94 |
| 2026-08-02 12:00 |
23:37:09.85 |
-62:40:58.5 |
HIP 116509 |
6.17 |
| 2026-08-03 00:00 |
23:36:58.31 |
-62:42:09.4 |
HIP 116509 |
4.39 |
| 2026-08-03 12:00 |
23:36:46.69 |
-62:43:19.9 |
HIP 116509 |
2.63 |
| 2026-08-04 00:00 |
23:36:34.99 |
-62:44:30.0 |
HIP 116509 |
0.90 |
| 2026-08-04 12:00 |
23:36:23.20 |
-62:45:39.5 |
HIP 116509 |
1.02 |
| 2026-08-05 00:00 |
23:36:11.33 |
-62:46:48.6 |
HIP 116509 |
2.76 |
| 2026-08-05 12:00 |
23:35:59.37 |
-62:47:57.3 |
HIP 116509 |
4.54 |
| 2026-08-06 00:00 |
23:35:47.34 |
-62:49:05.4 |
HIP 116509 |
6.32 |
| 2026-08-06 12:00 |
23:35:35.23 |
-62:50:13.1 |
HIP 116509 |
8.10 |
| 2026-08-07 00:00 |
23:35:23.03 |
-62:51:20.2 |
HIP 116509 |
9.88 |
| 2026-08-07 12:00 |
23:35:10.76 |
-62:52:26.9 |
HIP 116509 |
11.67 |
| 2026-08-08 00:00 |
23:34:58.41 |
-62:53:33.1 |
HIP 116509 |
13.46 |
| 2026-08-08 12:00 |
23:34:45.98 |
-62:54:38.7 |
HIP 116509 |
15.25 |
| 2026-08-09 00:00 |
23:34:33.47 |
-62:55:43.8 |
HIP 116509 |
17.04 |
| 2026-08-09 12:00 |
23:34:20.89 |
-62:56:48.4 |
HIP 116509 |
18.83 |
| 2026-08-10 00:00 |
23:34:08.23 |
-62:57:52.5 |
HIP 116110 |
17.59 |
| 2026-08-10 12:00 |
23:33:55.50 |
-62:58:56.1 |
HIP 116110 |
16.35 |
| 2026-08-11 00:00 |
23:33:42.69 |
-62:59:59.0 |
HIP 116110 |
15.21 |
| 2026-08-11 12:00 |
23:33:29.81 |
-63:01:01.5 |
HIP 116110 |
14.20 |
| 2026-08-12 00:00 |
23:33:16.86 |
-63:02:03.4 |
HIP 116110 |
13.34 |
| 2026-08-12 12:00 |
23:33:03.84 |
-63:03:04.7 |
HIP 116110 |
12.67 |
| 2026-08-13 00:00 |
23:32:50.75 |
-63:04:05.4 |
HIP 116110 |
12.22 |
| 2026-08-13 12:00 |
23:32:37.59 |
-63:05:05.6 |
HIP 116110 |
12.01 |
| 2026-08-14 00:00 |
23:32:24.36 |
-63:06:05.2 |
HIP 116110 |
12.06 |
| 2026-08-14 12:00 |
23:32:11.07 |
-63:07:04.2 |
HIP 116110 |
12.36 |
| 2026-08-15 00:00 |
23:31:57.71 |
-63:08:02.6 |
HIP 116248 |
12.86 |
| 2026-08-15 12:00 |
23:31:44.29 |
-63:09:00.4 |
HIP 116248 |
13.36 |
| 2026-08-16 00:00 |
23:31:30.80 |
-63:09:57.6 |
HIP 116248 |
14.08 |
| 2026-08-16 12:00 |
23:31:17.25 |
-63:10:54.2 |
HIP 116248 |
15.00 |
| 2026-08-17 00:00 |
23:31:03.64 |
-63:11:50.2 |
HIP 115908 |
14.80 |
| 2026-08-17 12:00 |
23:30:49.97 |
-63:12:45.6 |
HIP 115908 |
13.75 |
| 2026-08-18 00:00 |
23:30:36.23 |
-63:13:40.3 |
HIP 115908 |
12.85 |
| 2026-08-18 12:00 |
23:30:22.44 |
-63:14:34.5 |
HIP 115908 |
12.15 |
| 2026-08-19 00:00 |
23:30:08.60 |
-63:15:27.9 |
HIP 115908 |
11.67 |