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 |
0.806 |
| 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) |
| 2026-05-12 00:00 |
14:47:29.88 |
-34:48:04.4 |
HIP 72334 |
0.65 |
| 2026-05-12 12:00 |
14:47:23.56 |
-34:47:33.1 |
HIP 72334 |
1.22 |
| 2026-05-13 00:00 |
14:47:17.25 |
-34:47:01.6 |
HIP 72334 |
2.54 |
| 2026-05-13 12:00 |
14:47:10.95 |
-34:46:29.8 |
HIP 72334 |
3.91 |
| 2026-05-14 00:00 |
14:47:04.66 |
-34:45:57.7 |
HIP 72334 |
5.30 |
| 2026-05-14 12:00 |
14:46:58.38 |
-34:45:25.5 |
HIP 72334 |
6.69 |
| 2026-05-15 00:00 |
14:46:52.11 |
-34:44:53.0 |
HIP 72334 |
8.08 |
| 2026-05-15 12:00 |
14:46:45.86 |
-34:44:20.2 |
HIP 72334 |
9.47 |
| 2026-05-16 00:00 |
14:46:39.62 |
-34:43:47.2 |
HIP 72334 |
10.86 |
| 2026-05-16 12:00 |
14:46:33.39 |
-34:43:14.1 |
HIP 72334 |
12.26 |
| 2026-05-17 00:00 |
14:46:27.18 |
-34:42:40.6 |
HIP 72334 |
13.65 |
| 2026-05-17 12:00 |
14:46:20.99 |
-34:42:07.0 |
HIP 72334 |
15.03 |
| 2026-05-18 00:00 |
14:46:14.81 |
-34:41:33.2 |
HIP 72334 |
16.42 |
| 2026-05-18 12:00 |
14:46:08.65 |
-34:40:59.1 |
HIP 72334 |
17.81 |
| 2026-05-19 00:00 |
14:46:02.50 |
-34:40:24.8 |
HIP 72334 |
19.19 |
| 2026-05-19 12:00 |
14:45:56.38 |
-34:39:50.4 |
HIP 72334 |
20.58 |
| 2026-05-20 00:00 |
14:45:50.27 |
-34:39:15.7 |
HIP 72099 |
19.72 |
| 2026-05-20 12:00 |
14:45:44.18 |
-34:38:40.8 |
HIP 72099 |
18.55 |
| 2026-05-21 00:00 |
14:45:38.11 |
-34:38:05.8 |
HIP 72099 |
17.41 |
| 2026-05-21 12:00 |
14:45:32.07 |
-34:37:30.5 |
HIP 72099 |
16.31 |
| 2026-05-22 00:00 |
14:45:26.04 |
-34:36:55.0 |
HIP 72099 |
15.26 |
| 2026-05-22 12:00 |
14:45:20.03 |
-34:36:19.4 |
HIP 72099 |
14.25 |
| 2026-05-23 00:00 |
14:45:14.05 |
-34:35:43.6 |
HIP 72099 |
13.31 |
| 2026-05-23 12:00 |
14:45:08.09 |
-34:35:07.6 |
HIP 72099 |
12.45 |
| 2026-05-24 00:00 |
14:45:02.15 |
-34:34:31.4 |
HIP 72099 |
11.68 |
| 2026-05-24 12:00 |
14:44:56.24 |
-34:33:55.1 |
HIP 72099 |
11.03 |
| 2026-05-25 00:00 |
14:44:50.35 |
-34:33:18.6 |
HIP 72099 |
10.50 |
| 2026-05-25 12:00 |
14:44:44.49 |
-34:32:41.9 |
HIP 72099 |
10.13 |
| 2026-05-26 00:00 |
14:44:38.65 |
-34:32:05.0 |
HIP 72099 |
9.93 |
| 2026-05-26 12:00 |
14:44:32.83 |
-34:31:28.0 |
HIP 72099 |
9.90 |
| 2026-05-27 00:00 |
14:44:27.05 |
-34:30:50.9 |
HIP 72099 |
10.06 |
| 2026-05-27 12:00 |
14:44:21.29 |
-34:30:13.6 |
HIP 72099 |
10.38 |
| 2026-05-28 00:00 |
14:44:15.55 |
-34:29:36.1 |
HIP 72099 |
10.85 |
| 2026-05-28 12:00 |
14:44:09.85 |
-34:28:58.5 |
HIP 72099 |
11.45 |
| 2026-05-29 00:00 |
14:44:04.17 |
-34:28:20.7 |
HIP 72099 |
12.16 |
| 2026-05-29 12:00 |
14:43:58.52 |
-34:27:42.8 |
HIP 72099 |
12.97 |
| 2026-05-30 00:00 |
14:43:52.90 |
-34:27:04.8 |
HIP 72099 |
13.84 |
| 2026-05-30 12:00 |
14:43:47.31 |
-34:26:26.6 |
HIP 72099 |
14.78 |
| 2026-05-31 00:00 |
14:43:41.76 |
-34:25:48.4 |
HIP 72099 |
15.77 |
| 2026-05-31 12:00 |
14:43:36.23 |
-34:25:09.9 |
HIP 72099 |
16.79 |
| 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 |