361P/Spacewatch
メタデータ
| 項目 |
値 |
| Designation |
361P/Spacewatch |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2018-07-02T14:46:57.017280Z |
| Orbit solution date (soln_date, UTC) |
2023-02-13T23:14:08Z |
| Obs used |
381 |
| NEO |
- |
| M1 |
4.600 |
| K1 |
23.500 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2017-09-16.0000000 |
| e |
0.43788752 |
| q (au) |
2.780030 |
| a (au) |
4.945682 |
| i (deg) |
13.882834 |
| Ω (om, deg) |
203.277939 |
| ω (w, deg) |
219.242791 |
| M (ma, deg) |
334.047022 |
等級
散乱 + 全体線形
$$
M_a = (7.723 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
7.723 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.500 |
| 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
残差 (区間線形)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| 開始日 (UTC) |
終了日 (UTC) |
a |
b |
| 2017-09-11 |
2018-01-27 |
+17.2864 |
-8.358 |
| 2018-08-25 |
2019-02-19 |
+7.9293 |
-4.093 |
| 2019-02-19 |
2020-03-21 |
-2.5566 |
+1.565 |
log10 r = log10(太陽距離/AU)、Δ = 地球距離(AU)
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
18:37:09.51 |
-11:25:39.0 |
HIP 91340 |
10.69 |
| 2026-02-03 12:00 |
18:37:29.08 |
-11:24:47.1 |
HIP 91340 |
6.07 |
| 2026-02-04 00:00 |
18:37:48.58 |
-11:23:54.7 |
HIP 91340 |
2.63 |
| 2026-02-04 12:00 |
18:38:08.03 |
-11:23:01.9 |
HIP 91340 |
4.91 |
| 2026-02-05 00:00 |
18:38:27.42 |
-11:22:08.6 |
HIP 91340 |
9.38 |
| 2026-02-05 12:00 |
18:38:46.75 |
-11:21:14.9 |
HIP 91340 |
14.08 |
| 2026-02-06 00:00 |
18:39:06.02 |
-11:20:20.8 |
HIP 91530 |
18.63 |
| 2026-02-06 12:00 |
18:39:25.22 |
-11:19:26.2 |
HIP 91530 |
15.11 |
| 2026-02-07 00:00 |
18:39:44.37 |
-11:18:31.2 |
HIP 91530 |
12.46 |
| 2026-02-07 12:00 |
18:40:03.45 |
-11:17:35.7 |
HIP 91530 |
11.30 |
| 2026-02-08 00:00 |
18:40:22.46 |
-11:16:39.8 |
HIP 91530 |
12.06 |
| 2026-02-08 12:00 |
18:40:41.42 |
-11:15:43.5 |
HIP 91530 |
14.42 |
| 2026-02-09 00:00 |
18:41:00.30 |
-11:14:46.8 |
HIP 91625 |
14.27 |
| 2026-02-09 12:00 |
18:41:19.12 |
-11:13:49.6 |
HIP 91625 |
13.26 |
| 2026-02-10 00:00 |
18:41:37.88 |
-11:12:52.0 |
HIP 91625 |
13.85 |
| 2026-02-10 12:00 |
18:41:56.56 |
-11:11:54.0 |
HIP 91740 |
9.46 |
| 2026-02-11 00:00 |
18:42:15.18 |
-11:10:55.6 |
HIP 91740 |
5.41 |
| 2026-02-11 12:00 |
18:42:33.73 |
-11:09:56.8 |
HIP 91740 |
3.53 |
| 2026-02-12 00:00 |
18:42:52.20 |
-11:08:57.6 |
HIP 91740 |
6.22 |
| 2026-02-12 12:00 |
18:43:10.61 |
-11:07:57.9 |
HIP 91740 |
10.38 |
| 2026-02-13 00:00 |
18:43:28.94 |
-11:06:57.9 |
HIP 91847 |
13.27 |
| 2026-02-13 12:00 |
18:43:47.20 |
-11:05:57.4 |
HIP 91847 |
14.77 |
| 2026-02-14 00:00 |
18:44:05.39 |
-11:04:56.5 |
HIP 91847 |
17.38 |
| 2026-02-14 12:00 |
18:44:23.50 |
-11:03:55.3 |
HIP 91847 |
20.68 |
| 2026-02-15 00:00 |
18:44:41.53 |
-11:02:53.6 |
HIP 91847 |
24.38 |
| 2026-02-15 12:00 |
18:44:59.49 |
-11:01:51.6 |
HIP 92000 |
25.47 |
| 2026-02-16 00:00 |
18:45:17.37 |
-11:00:49.1 |
HIP 91961 |
25.73 |
| 2026-02-16 12:00 |
18:45:35.18 |
-10:59:46.3 |
HIP 91961 |
26.64 |
| 2026-02-17 00:00 |
18:45:52.90 |
-10:58:43.1 |
HIP 92179 |
24.38 |
| 2026-02-17 12:00 |
18:46:10.55 |
-10:57:39.5 |
HIP 92179 |
21.75 |
| 2026-02-18 00:00 |
18:46:28.11 |
-10:56:35.6 |
HIP 92179 |
19.81 |
| 2026-02-18 12:00 |
18:46:45.60 |
-10:55:31.3 |
HIP 92179 |
18.75 |
| 2026-02-19 00:00 |
18:47:03.00 |
-10:54:26.6 |
HIP 92179 |
18.71 |
| 2026-02-19 12:00 |
18:47:20.31 |
-10:53:21.5 |
HIP 92179 |
19.69 |
| 2026-02-20 00:00 |
18:47:37.55 |
-10:52:16.1 |
HIP 92179 |
21.53 |
| 2026-02-20 12:00 |
18:47:54.70 |
-10:51:10.3 |
HIP 92179 |
24.03 |
| 2026-02-21 00:00 |
18:48:11.76 |
-10:50:04.1 |
HIP 92179 |
27.00 |
| 2026-02-21 12:00 |
18:48:28.74 |
-10:48:57.7 |
HIP 92179 |
30.29 |
| 2026-02-22 00:00 |
18:48:45.63 |
-10:47:50.8 |
HIP 92377 |
27.52 |
| 2026-02-22 12:00 |
18:49:02.43 |
-10:46:43.6 |
HIP 92377 |
25.01 |
| 2026-02-23 00:00 |
18:49:19.14 |
-10:45:36.1 |
HIP 92453 |
22.51 |
| 2026-02-23 12:00 |
18:49:35.76 |
-10:44:28.2 |
HIP 92453 |
20.48 |
| 2026-02-24 00:00 |
18:49:52.30 |
-10:43:20.0 |
HIP 92453 |
19.20 |