メタデータ
| 項目 |
値 |
| Designation |
C/1999 S2 (McNaught-Watson) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1997-11-22T14:49:59.252160Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:02Z |
| Obs used |
88 |
| NEO |
- |
| M1 |
8.000 |
| K1 |
4.500 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2000-03-17.0000000 |
| e |
1.00527083 |
| q (au) |
6.467743 |
| a (au) |
-1227.083165 |
| i (deg) |
65.820220 |
| Ω (om, deg) |
74.460976 |
| ω (w, deg) |
223.497414 |
| M (ma, deg) |
0.019384 |
等級
散乱 + 全体線形
$$
M_a = (12.224 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
12.224 |
| n |
2.000 |
| gf |
0.977 |
| gb |
-0.827 |
| k |
0.800 |
| δ90 |
9.955 |
| 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) |
| 2026-09-20 00:00 |
04:57:15.15 |
+22:32:47.0 |
HIP 22935 |
15.93 |
| 2026-09-20 12:00 |
04:57:14.63 |
+22:32:48.8 |
HIP 22935 |
15.80 |
| 2026-09-21 00:00 |
04:57:14.09 |
+22:32:50.5 |
HIP 22935 |
15.68 |
| 2026-09-21 12:00 |
04:57:13.52 |
+22:32:52.2 |
HIP 22935 |
15.54 |
| 2026-09-22 00:00 |
04:57:12.93 |
+22:32:53.9 |
HIP 22935 |
15.41 |
| 2026-09-22 12:00 |
04:57:12.32 |
+22:32:55.6 |
HIP 22935 |
15.26 |
| 2026-09-23 00:00 |
04:57:11.69 |
+22:32:57.2 |
HIP 22935 |
15.11 |
| 2026-09-23 12:00 |
04:57:11.03 |
+22:32:58.8 |
HIP 22935 |
14.96 |
| 2026-09-24 00:00 |
04:57:10.35 |
+22:33:00.3 |
HIP 22935 |
14.80 |
| 2026-09-24 12:00 |
04:57:09.65 |
+22:33:01.8 |
HIP 22935 |
14.64 |
| 2026-09-25 00:00 |
04:57:08.93 |
+22:33:03.3 |
HIP 22935 |
14.47 |
| 2026-09-25 12:00 |
04:57:08.19 |
+22:33:04.7 |
HIP 22935 |
14.30 |
| 2026-09-26 00:00 |
04:57:07.42 |
+22:33:06.2 |
HIP 22935 |
14.12 |
| 2026-09-26 12:00 |
04:57:06.63 |
+22:33:07.5 |
HIP 22935 |
13.93 |
| 2026-09-27 00:00 |
04:57:05.82 |
+22:33:08.9 |
HIP 22935 |
13.75 |
| 2026-09-27 12:00 |
04:57:04.98 |
+22:33:10.2 |
HIP 22935 |
13.55 |
| 2026-09-28 00:00 |
04:57:04.13 |
+22:33:11.5 |
HIP 22935 |
13.35 |
| 2026-09-28 12:00 |
04:57:03.25 |
+22:33:12.8 |
HIP 22935 |
13.15 |
| 2026-09-29 00:00 |
04:57:02.35 |
+22:33:14.0 |
HIP 22935 |
12.94 |
| 2026-09-29 12:00 |
04:57:01.43 |
+22:33:15.2 |
HIP 22935 |
12.73 |
| 2026-09-30 00:00 |
04:57:00.48 |
+22:33:16.3 |
HIP 22935 |
12.51 |
| 2026-09-30 12:00 |
04:56:59.52 |
+22:33:17.4 |
HIP 22935 |
12.28 |
| 2026-10-01 00:00 |
04:56:58.53 |
+22:33:18.5 |
HIP 22935 |
12.06 |
| 2026-10-01 12:00 |
04:56:57.52 |
+22:33:19.6 |
HIP 22935 |
11.82 |
| 2026-10-02 00:00 |
04:56:56.49 |
+22:33:20.6 |
HIP 22935 |
11.58 |
| 2026-10-02 12:00 |
04:56:55.44 |
+22:33:21.6 |
HIP 22935 |
11.34 |
| 2026-10-03 00:00 |
04:56:54.36 |
+22:33:22.6 |
HIP 22935 |
11.09 |
| 2026-10-03 12:00 |
04:56:53.27 |
+22:33:23.5 |
HIP 22935 |
10.84 |
| 2026-10-04 00:00 |
04:56:52.15 |
+22:33:24.4 |
HIP 22935 |
10.58 |
| 2026-10-04 12:00 |
04:56:51.01 |
+22:33:25.3 |
HIP 22935 |
10.32 |
| 2026-10-05 00:00 |
04:56:49.85 |
+22:33:26.1 |
HIP 22935 |
10.05 |
| 2026-10-05 12:00 |
04:56:48.67 |
+22:33:26.9 |
HIP 22935 |
9.78 |
| 2026-10-06 00:00 |
04:56:47.47 |
+22:33:27.7 |
HIP 22935 |
9.50 |
| 2026-10-06 12:00 |
04:56:46.24 |
+22:33:28.4 |
HIP 22935 |
9.22 |
| 2026-10-07 00:00 |
04:56:45.00 |
+22:33:29.1 |
HIP 22935 |
8.93 |
| 2026-10-07 12:00 |
04:56:43.73 |
+22:33:29.8 |
HIP 22935 |
8.64 |
| 2026-10-08 00:00 |
04:56:42.44 |
+22:33:30.4 |
HIP 22935 |
8.34 |
| 2026-10-08 12:00 |
04:56:41.13 |
+22:33:31.0 |
HIP 22935 |
8.04 |
| 2026-10-09 00:00 |
04:56:39.81 |
+22:33:31.6 |
HIP 22935 |
7.74 |
| 2026-10-09 12:00 |
04:56:38.46 |
+22:33:32.1 |
HIP 22935 |
7.43 |
| 2026-10-10 00:00 |
04:56:37.09 |
+22:33:32.7 |
HIP 22935 |
7.11 |
| 2026-10-10 12:00 |
04:56:35.69 |
+22:33:33.1 |
HIP 22935 |
6.80 |
| 2026-10-11 00:00 |
04:56:34.28 |
+22:33:33.6 |
HIP 22935 |
6.47 |