メタデータ
| 項目 |
値 |
| Designation |
491P/Spacewatch-PANSTARRS |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2024-09-06T09:18:42.033600Z |
| Orbit solution date (soln_date, UTC) |
2026-05-28T12:12:26Z |
| Obs used |
458 |
| NEO |
- |
| M1 |
11.000 |
| K1 |
8.250 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2024-05-30T08:01:15.830400Z |
| Discovery magnitude (MPC) |
21.20 w |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2020-12-17.0000000 |
| e |
0.25973782 |
| q (au) |
3.709980 |
| a (au) |
5.011711 |
| i (deg) |
9.371340 |
| Ω (om, deg) |
311.733466 |
| ω (w, deg) |
299.087899 |
| M (ma, deg) |
240.582366 |
等級
散乱 + 全体線形
$$
M_a = (12.212 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
12.212 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.965 |
| 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
ファインディングチャート
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
23:07:22.82 |
-01:40:55.0 |
HIP 114202 |
25.79 |
| 2026-06-01 12:00 |
23:07:34.89 |
-01:38:45.3 |
HIP 114202 |
27.61 |
| 2026-06-02 00:00 |
23:07:46.79 |
-01:36:36.4 |
HIP 114202 |
29.76 |
| 2026-06-02 12:00 |
23:07:58.53 |
-01:34:28.3 |
HIP 114202 |
32.17 |
| 2026-06-03 00:00 |
23:08:10.10 |
-01:32:21.2 |
HIP 114202 |
34.77 |
| 2026-06-03 12:00 |
23:08:21.51 |
-01:30:14.8 |
HIP 114202 |
37.50 |
| 2026-06-04 00:00 |
23:08:32.76 |
-01:28:09.4 |
HIP 114202 |
40.34 |
| 2026-06-04 12:00 |
23:08:43.84 |
-01:26:04.7 |
HIP 114202 |
43.24 |
| 2026-06-05 00:00 |
23:08:54.75 |
-01:24:01.0 |
HIP 114517 |
44.62 |
| 2026-06-05 12:00 |
23:09:05.49 |
-01:21:58.2 |
HIP 114517 |
41.39 |
| 2026-06-06 00:00 |
23:09:16.07 |
-01:19:56.2 |
HIP 114517 |
38.24 |
| 2026-06-06 12:00 |
23:09:26.48 |
-01:17:55.1 |
HIP 114517 |
35.15 |
| 2026-06-07 00:00 |
23:09:36.71 |
-01:15:55.0 |
HIP 114517 |
32.16 |
| 2026-06-07 12:00 |
23:09:46.78 |
-01:13:55.7 |
HIP 114517 |
29.27 |
| 2026-06-08 00:00 |
23:09:56.67 |
-01:11:57.3 |
HIP 114517 |
26.49 |
| 2026-06-08 12:00 |
23:10:06.40 |
-01:10:00.0 |
HIP 114517 |
23.85 |
| 2026-06-09 00:00 |
23:10:15.95 |
-01:08:03.4 |
HIP 114517 |
21.38 |
| 2026-06-09 12:00 |
23:10:25.32 |
-01:06:07.8 |
HIP 114517 |
19.14 |
| 2026-06-10 00:00 |
23:10:34.52 |
-01:04:13.2 |
HIP 114517 |
17.18 |
| 2026-06-10 12:00 |
23:10:43.54 |
-01:02:19.5 |
HIP 114517 |
15.58 |
| 2026-06-11 00:00 |
23:10:52.39 |
-01:00:26.8 |
HIP 114517 |
14.45 |
| 2026-06-11 12:00 |
23:11:01.06 |
-00:58:35.0 |
HIP 114517 |
13.86 |
| 2026-06-12 00:00 |
23:11:09.56 |
-00:56:44.2 |
HIP 114517 |
13.87 |
| 2026-06-12 12:00 |
23:11:17.87 |
-00:54:54.4 |
HIP 114517 |
14.43 |
| 2026-06-13 00:00 |
23:11:26.00 |
-00:53:05.5 |
HIP 114517 |
15.47 |
| 2026-06-13 12:00 |
23:11:33.96 |
-00:51:17.7 |
HIP 114517 |
16.88 |
| 2026-06-14 00:00 |
23:11:41.73 |
-00:49:30.8 |
HIP 114517 |
18.56 |
| 2026-06-14 12:00 |
23:11:49.32 |
-00:47:44.9 |
HIP 114517 |
20.42 |
| 2026-06-15 00:00 |
23:11:56.73 |
-00:46:00.1 |
HIP 114517 |
22.40 |
| 2026-06-15 12:00 |
23:12:03.95 |
-00:44:16.2 |
HIP 114609 |
23.77 |
| 2026-06-16 00:00 |
23:12:10.99 |
-00:42:33.4 |
HIP 114609 |
21.33 |
| 2026-06-16 12:00 |
23:12:17.85 |
-00:40:51.6 |
HIP 114609 |
18.93 |
| 2026-06-17 00:00 |
23:12:24.52 |
-00:39:10.9 |
HIP 114609 |
16.58 |
| 2026-06-17 12:00 |
23:12:31.01 |
-00:37:31.1 |
HIP 114609 |
14.28 |
| 2026-06-18 00:00 |
23:12:37.31 |
-00:35:52.4 |
HIP 114609 |
12.02 |
| 2026-06-18 12:00 |
23:12:43.43 |
-00:34:14.8 |
HIP 114609 |
9.81 |
| 2026-06-19 00:00 |
23:12:49.35 |
-00:32:38.2 |
HIP 114609 |
7.66 |
| 2026-06-19 12:00 |
23:12:55.10 |
-00:31:02.6 |
HIP 114609 |
5.57 |
| 2026-06-20 00:00 |
23:13:00.65 |
-00:29:28.1 |
HIP 114609 |
3.58 |
| 2026-06-20 12:00 |
23:13:06.02 |
-00:27:54.7 |
HIP 114609 |
1.86 |
| 2026-06-21 00:00 |
23:13:11.19 |
-00:26:22.3 |
HIP 114609 |
1.55 |
| 2026-06-21 12:00 |
23:13:16.18 |
-00:24:51.1 |
HIP 114609 |
3.02 |
| 2026-06-22 00:00 |
23:13:20.99 |
-00:23:20.8 |
HIP 114609 |
4.81 |