メタデータ
| 項目 |
値 |
| Designation |
C/2007 S2 (Lemmon) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2008-09-14T20:38:31.534080Z |
| Orbit solution date (soln_date, UTC) |
2024-04-13T16:42:27Z |
| Obs used |
423 |
| NEO |
- |
| M1 |
10.500 |
| K1 |
6.000 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2008-07-02.0000000 |
| e |
0.55701356 |
| q (au) |
5.557956 |
| a (au) |
12.546561 |
| i (deg) |
16.862815 |
| Ω (om, deg) |
296.252831 |
| ω (w, deg) |
210.466010 |
| M (ma, deg) |
358.339773 |
等級
散乱 + 全体線形
$$
M_a = (9.208 + 2.571\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
9.208 |
| n |
2.571 |
| gf |
1.000 |
| gb |
-0.969 |
| 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 |
20:59:44.43 |
-11:18:38.7 |
HIP 103671 |
20.17 |
| 2026-07-29 12:00 |
20:59:38.99 |
-11:18:56.5 |
HIP 103671 |
21.05 |
| 2026-07-30 00:00 |
20:59:33.55 |
-11:19:14.3 |
HIP 103671 |
21.98 |
| 2026-07-30 12:00 |
20:59:28.10 |
-11:19:32.3 |
HIP 103671 |
22.95 |
| 2026-07-31 00:00 |
20:59:22.65 |
-11:19:50.4 |
HIP 103671 |
23.97 |
| 2026-07-31 12:00 |
20:59:17.19 |
-11:20:08.6 |
HIP 103671 |
25.02 |
| 2026-08-01 00:00 |
20:59:11.72 |
-11:20:26.8 |
HIP 103671 |
26.10 |
| 2026-08-01 12:00 |
20:59:06.25 |
-11:20:45.2 |
HIP 103671 |
27.21 |
| 2026-08-02 00:00 |
20:59:00.78 |
-11:21:03.6 |
HIP 103671 |
28.35 |
| 2026-08-02 12:00 |
20:58:55.30 |
-11:21:22.2 |
HIP 103671 |
29.51 |
| 2026-08-03 00:00 |
20:58:49.82 |
-11:21:40.8 |
HIP 103671 |
30.69 |
| 2026-08-03 12:00 |
20:58:44.34 |
-11:21:59.5 |
HIP 103671 |
31.88 |
| 2026-08-04 00:00 |
20:58:38.86 |
-11:22:18.3 |
HIP 103671 |
33.10 |
| 2026-08-04 12:00 |
20:58:33.38 |
-11:22:37.2 |
HIP 103671 |
34.32 |
| 2026-08-05 00:00 |
20:58:27.89 |
-11:22:56.1 |
HIP 103487 |
34.94 |
| 2026-08-05 12:00 |
20:58:22.41 |
-11:23:15.2 |
HIP 103487 |
34.41 |
| 2026-08-06 00:00 |
20:58:16.92 |
-11:23:34.3 |
HIP 103487 |
33.92 |
| 2026-08-06 12:00 |
20:58:11.44 |
-11:23:53.5 |
HIP 103487 |
33.48 |
| 2026-08-07 00:00 |
20:58:05.95 |
-11:24:12.7 |
HIP 103487 |
33.10 |
| 2026-08-07 12:00 |
20:58:00.47 |
-11:24:32.0 |
HIP 103487 |
32.76 |
| 2026-08-08 00:00 |
20:57:54.99 |
-11:24:51.4 |
HIP 103487 |
32.48 |
| 2026-08-08 12:00 |
20:57:49.51 |
-11:25:10.9 |
HIP 103487 |
32.26 |
| 2026-08-09 00:00 |
20:57:44.04 |
-11:25:30.4 |
HIP 103487 |
32.09 |
| 2026-08-09 12:00 |
20:57:38.57 |
-11:25:50.0 |
HIP 103487 |
31.98 |
| 2026-08-10 00:00 |
20:57:33.11 |
-11:26:09.6 |
HIP 103487 |
31.92 |
| 2026-08-10 12:00 |
20:57:27.65 |
-11:26:29.3 |
HIP 103280 |
31.15 |
| 2026-08-11 00:00 |
20:57:22.19 |
-11:26:49.1 |
HIP 103280 |
29.94 |
| 2026-08-11 12:00 |
20:57:16.75 |
-11:27:08.9 |
HIP 103280 |
28.74 |
| 2026-08-12 00:00 |
20:57:11.30 |
-11:27:28.7 |
HIP 103280 |
27.57 |
| 2026-08-12 12:00 |
20:57:05.87 |
-11:27:48.6 |
HIP 103280 |
26.42 |
| 2026-08-13 00:00 |
20:57:00.44 |
-11:28:08.5 |
HIP 103280 |
25.29 |
| 2026-08-13 12:00 |
20:56:55.02 |
-11:28:28.5 |
HIP 103280 |
24.19 |
| 2026-08-14 00:00 |
20:56:49.62 |
-11:28:48.5 |
HIP 103280 |
23.12 |
| 2026-08-14 12:00 |
20:56:44.22 |
-11:29:08.6 |
HIP 103280 |
22.09 |
| 2026-08-15 00:00 |
20:56:38.83 |
-11:29:28.7 |
HIP 103280 |
21.10 |
| 2026-08-15 12:00 |
20:56:33.45 |
-11:29:48.8 |
HIP 103280 |
20.15 |
| 2026-08-16 00:00 |
20:56:28.08 |
-11:30:08.9 |
HIP 103280 |
19.25 |
| 2026-08-16 12:00 |
20:56:22.72 |
-11:30:29.1 |
HIP 103280 |
18.41 |
| 2026-08-17 00:00 |
20:56:17.38 |
-11:30:49.3 |
HIP 103280 |
17.65 |
| 2026-08-17 12:00 |
20:56:12.04 |
-11:31:09.5 |
HIP 103280 |
16.95 |
| 2026-08-18 00:00 |
20:56:06.73 |
-11:31:29.7 |
HIP 103280 |
16.34 |
| 2026-08-18 12:00 |
20:56:01.42 |
-11:31:50.0 |
HIP 103280 |
15.82 |
| 2026-08-19 00:00 |
20:55:56.13 |
-11:32:10.3 |
HIP 103280 |
15.41 |