メタデータ
| 項目 |
値 |
| Designation |
31P/Schwassmann-Wachmann 2 |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2010-09-29T11:16:57.953280Z |
| Orbit solution date (soln_date, UTC) |
2025-11-23T22:21:40Z |
| Obs used |
1028 |
| NEO |
- |
| M1 |
4.200 |
| K1 |
23.000 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2011-02-16.0000000 |
| e |
0.19303098 |
| q (au) |
3.424308 |
| a (au) |
4.243419 |
| i (deg) |
4.546365 |
| Ω (om, deg) |
114.186460 |
| ω (w, deg) |
17.932787 |
| M (ma, deg) |
15.732489 |
等級
散乱 + 全体線形
$$
M_a = (14.954 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
14.954 |
| n |
2.000 |
| gf |
0.962 |
| gb |
-0.501 |
| k |
1.000 |
| δ90 |
9.174 |
| 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 |
02:21:49.35 |
+10:15:27.3 |
HIP 10937 |
20.51 |
| 2026-05-12 12:00 |
02:22:21.25 |
+10:18:06.7 |
HIP 11194 |
26.90 |
| 2026-05-13 00:00 |
02:22:53.14 |
+10:20:45.6 |
HIP 11194 |
19.50 |
| 2026-05-13 12:00 |
02:23:25.04 |
+10:23:24.1 |
HIP 11194 |
13.19 |
| 2026-05-14 00:00 |
02:23:56.93 |
+10:26:02.2 |
HIP 11194 |
10.23 |
| 2026-05-14 12:00 |
02:24:28.82 |
+10:28:39.8 |
HIP 11249 |
9.40 |
| 2026-05-15 00:00 |
02:25:00.71 |
+10:31:16.9 |
HIP 11249 |
6.07 |
| 2026-05-15 12:00 |
02:25:32.59 |
+10:33:53.6 |
HIP 11319 |
4.14 |
| 2026-05-16 00:00 |
02:26:04.47 |
+10:36:29.9 |
HIP 11319 |
8.35 |
| 2026-05-16 12:00 |
02:26:36.34 |
+10:39:05.7 |
HIP 11390 |
5.66 |
| 2026-05-17 00:00 |
02:27:08.21 |
+10:41:41.0 |
HIP 11390 |
9.54 |
| 2026-05-17 12:00 |
02:27:40.07 |
+10:44:15.9 |
HIP 11506 |
14.48 |
| 2026-05-18 00:00 |
02:28:11.93 |
+10:46:50.2 |
HIP 11506 |
13.01 |
| 2026-05-18 12:00 |
02:28:43.77 |
+10:49:24.1 |
HIP 11506 |
16.26 |
| 2026-05-19 00:00 |
02:29:15.61 |
+10:51:57.6 |
HIP 11665 |
21.47 |
| 2026-05-19 12:00 |
02:29:47.44 |
+10:54:30.5 |
HIP 11665 |
13.71 |
| 2026-05-20 00:00 |
02:30:19.25 |
+10:57:03.0 |
HIP 11665 |
7.08 |
| 2026-05-20 12:00 |
02:30:51.06 |
+10:59:34.9 |
HIP 11665 |
6.87 |
| 2026-05-21 00:00 |
02:31:22.86 |
+11:02:06.4 |
HIP 11665 |
13.37 |
| 2026-05-21 12:00 |
02:31:54.64 |
+11:04:37.4 |
HIP 11665 |
21.09 |
| 2026-05-22 00:00 |
02:32:26.42 |
+11:07:07.8 |
HIP 11665 |
29.06 |
| 2026-05-22 12:00 |
02:32:58.17 |
+11:09:37.8 |
HIP 11985 |
33.70 |
| 2026-05-23 00:00 |
02:33:29.92 |
+11:12:07.3 |
HIP 11971 |
27.80 |
| 2026-05-23 12:00 |
02:34:01.65 |
+11:14:36.2 |
HIP 11971 |
22.49 |
| 2026-05-24 00:00 |
02:34:33.37 |
+11:17:04.7 |
HIP 11971 |
19.30 |
| 2026-05-24 12:00 |
02:35:05.07 |
+11:19:32.6 |
HIP 11971 |
19.30 |
| 2026-05-25 00:00 |
02:35:36.76 |
+11:22:00.0 |
HIP 11971 |
22.48 |
| 2026-05-25 12:00 |
02:36:08.43 |
+11:24:27.0 |
HIP 12194 |
24.73 |
| 2026-05-26 00:00 |
02:36:40.09 |
+11:26:53.3 |
HIP 12194 |
23.97 |
| 2026-05-26 12:00 |
02:37:11.72 |
+11:29:19.2 |
HIP 12291 |
23.34 |
| 2026-05-27 00:00 |
02:37:43.34 |
+11:31:44.6 |
HIP 12291 |
16.50 |
| 2026-05-27 12:00 |
02:38:14.94 |
+11:34:09.4 |
HIP 12291 |
11.46 |
| 2026-05-28 00:00 |
02:38:46.53 |
+11:36:33.7 |
HIP 12291 |
11.05 |
| 2026-05-28 12:00 |
02:39:18.09 |
+11:38:57.5 |
HIP 12291 |
15.62 |
| 2026-05-29 00:00 |
02:39:49.64 |
+11:41:20.7 |
HIP 12291 |
22.28 |
| 2026-05-29 12:00 |
02:40:21.16 |
+11:43:43.4 |
HIP 12291 |
29.65 |
| 2026-05-30 00:00 |
02:40:52.67 |
+11:46:05.6 |
HIP 12291 |
37.31 |
| 2026-05-30 12:00 |
02:41:24.15 |
+11:48:27.2 |
HIP 12740 |
37.67 |
| 2026-05-31 00:00 |
02:41:55.61 |
+11:50:48.3 |
HIP 12740 |
29.64 |
| 2026-05-31 12:00 |
02:42:27.05 |
+11:53:08.8 |
HIP 12740 |
21.64 |
| 2026-06-01 00:00 |
02:42:58.47 |
+11:55:28.8 |
HIP 12740 |
13.69 |
| 2026-06-01 12:00 |
02:43:29.87 |
+11:57:48.2 |
HIP 12740 |
5.99 |
| 2026-06-02 00:00 |
02:44:01.24 |
+12:00:07.1 |
HIP 12740 |
3.60 |