メタデータ
| 項目 |
値 |
| Designation |
C/2015 X4 (Elenin) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2015-11-03T11:14:21.828480Z |
| Orbit solution date (soln_date, UTC) |
2022-05-19T21:12:39Z |
| Obs used |
607 |
| NEO |
- |
| M1 |
13.000 |
| 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) |
2016-02-01.0000000 |
| e |
0.81280434 |
| q (au) |
3.394686 |
| a (au) |
18.134427 |
| i (deg) |
29.504921 |
| Ω (om, deg) |
262.635812 |
| ω (w, deg) |
176.329174 |
| M (ma, deg) |
1.142681 |
等級
散乱 + 全体線形
$$
M_a = (11.919 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
11.919 |
| n |
2.000 |
| gf |
0.807 |
| gb |
-0.500 |
| k |
0.997 |
| δ90 |
1.000 |
| 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 |
| 2014-12-22 |
2015-11-02 |
+10.5196 |
-3.568 |
| 2015-12-02 |
2017-03-24 |
-2.7904 |
+1.550 |
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) |
| 2026-06-01 00:00 |
14:43:30.73 |
-34:24:31.4 |
HIP 72038 |
17.16 |
| 2026-06-01 12:00 |
14:43:25.26 |
-34:23:52.7 |
HIP 72038 |
17.15 |
| 2026-06-02 00:00 |
14:43:19.83 |
-34:23:13.9 |
HIP 72038 |
17.24 |
| 2026-06-02 12:00 |
14:43:14.43 |
-34:22:35.0 |
HIP 72038 |
17.42 |
| 2026-06-03 00:00 |
14:43:09.06 |
-34:21:56.0 |
HIP 72038 |
17.69 |
| 2026-06-03 12:00 |
14:43:03.72 |
-34:21:16.9 |
HIP 72038 |
18.03 |
| 2026-06-04 00:00 |
14:42:58.42 |
-34:20:37.7 |
HIP 72038 |
18.46 |
| 2026-06-04 12:00 |
14:42:53.15 |
-34:19:58.3 |
HIP 72038 |
18.95 |
| 2026-06-05 00:00 |
14:42:47.92 |
-34:19:18.9 |
HIP 72038 |
19.51 |
| 2026-06-05 12:00 |
14:42:42.72 |
-34:18:39.4 |
HIP 72038 |
20.12 |
| 2026-06-06 00:00 |
14:42:37.56 |
-34:17:59.8 |
HIP 72038 |
20.79 |
| 2026-06-06 12:00 |
14:42:32.43 |
-34:17:20.1 |
HIP 72038 |
21.50 |
| 2026-06-07 00:00 |
14:42:27.34 |
-34:16:40.3 |
HIP 72038 |
22.25 |
| 2026-06-07 12:00 |
14:42:22.29 |
-34:16:00.4 |
HIP 71815 |
22.48 |
| 2026-06-08 00:00 |
14:42:17.27 |
-34:15:20.5 |
HIP 71815 |
21.37 |
| 2026-06-08 12:00 |
14:42:12.29 |
-34:14:40.5 |
HIP 71815 |
20.28 |
| 2026-06-09 00:00 |
14:42:07.35 |
-34:14:00.4 |
HIP 71815 |
19.20 |
| 2026-06-09 12:00 |
14:42:02.45 |
-34:13:20.2 |
HIP 71815 |
18.15 |
| 2026-06-10 00:00 |
14:41:57.59 |
-34:12:40.0 |
HIP 71815 |
17.11 |
| 2026-06-10 12:00 |
14:41:52.76 |
-34:11:59.7 |
HIP 71815 |
16.11 |
| 2026-06-11 00:00 |
14:41:47.98 |
-34:11:19.4 |
HIP 71815 |
15.13 |
| 2026-06-11 12:00 |
14:41:43.24 |
-34:10:39.0 |
HIP 71815 |
14.19 |
| 2026-06-12 00:00 |
14:41:38.54 |
-34:09:58.6 |
HIP 71815 |
13.30 |
| 2026-06-12 12:00 |
14:41:33.88 |
-34:09:18.1 |
HIP 71815 |
12.45 |
| 2026-06-13 00:00 |
14:41:29.26 |
-34:08:37.5 |
HIP 71815 |
11.65 |
| 2026-06-13 12:00 |
14:41:24.68 |
-34:07:57.0 |
HIP 71815 |
10.93 |
| 2026-06-14 00:00 |
14:41:20.14 |
-34:07:16.4 |
HIP 71815 |
10.29 |
| 2026-06-14 12:00 |
14:41:15.65 |
-34:06:35.7 |
HIP 71815 |
9.73 |
| 2026-06-15 00:00 |
14:41:11.20 |
-34:05:55.1 |
HIP 71815 |
9.29 |
| 2026-06-15 12:00 |
14:41:06.80 |
-34:05:14.4 |
HIP 71815 |
8.97 |
| 2026-06-16 00:00 |
14:41:02.44 |
-34:04:33.7 |
HIP 71815 |
8.78 |
| 2026-06-16 12:00 |
14:40:58.12 |
-34:03:53.0 |
HIP 71815 |
8.72 |
| 2026-06-17 00:00 |
14:40:53.85 |
-34:03:12.2 |
HIP 71815 |
8.81 |
| 2026-06-17 12:00 |
14:40:49.63 |
-34:02:31.5 |
HIP 71815 |
9.02 |
| 2026-06-18 00:00 |
14:40:45.45 |
-34:01:50.7 |
HIP 71815 |
9.36 |
| 2026-06-18 12:00 |
14:40:41.31 |
-34:01:10.0 |
HIP 71815 |
9.79 |
| 2026-06-19 00:00 |
14:40:37.23 |
-34:00:29.2 |
HIP 71815 |
10.32 |
| 2026-06-19 12:00 |
14:40:33.19 |
-33:59:48.5 |
HIP 71815 |
10.92 |
| 2026-06-20 00:00 |
14:40:29.19 |
-33:59:07.7 |
HIP 71815 |
11.58 |
| 2026-06-20 12:00 |
14:40:25.24 |
-33:58:27.0 |
HIP 71815 |
12.29 |
| 2026-06-21 00:00 |
14:40:21.34 |
-33:57:46.3 |
HIP 71815 |
13.04 |
| 2026-06-21 12:00 |
14:40:17.49 |
-33:57:05.6 |
HIP 71815 |
13.82 |
| 2026-06-22 00:00 |
14:40:13.69 |
-33:56:25.0 |
HIP 71815 |
14.62 |