メタデータ
| 項目 |
値 |
| Designation |
C/2015 XY1 (Lemmon) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2018-04-29T23:09:25.130880Z |
| Orbit solution date (soln_date, UTC) |
2022-07-31T01:42:27Z |
| Obs used |
741 |
| NEO |
- |
| M1 |
6.400 |
| K1 |
8.250 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2018-03-20.0000000 |
| e |
1.00401907 |
| q (au) |
7.927954 |
| a (au) |
-1972.582314 |
| i (deg) |
148.846771 |
| Ω (om, deg) |
281.616004 |
| ω (w, deg) |
196.354336 |
| M (ma, deg) |
-0.000461 |
等級
散乱 + 全体線形
$$
M_a = (-0.857 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
-0.857 |
| n |
6.000 |
| gf |
0.882 |
| gb |
-0.939 |
| k |
1.000 |
| δ90 |
3.911 |
| 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 |
00:06:14.73 |
-29:52:10.0 |
HIP 477 |
8.80 |
| 2026-05-12 12:00 |
00:06:17.52 |
-29:52:31.2 |
HIP 477 |
9.07 |
| 2026-05-13 00:00 |
00:06:20.27 |
-29:52:53.0 |
HIP 477 |
9.38 |
| 2026-05-13 12:00 |
00:06:22.97 |
-29:53:15.2 |
HIP 477 |
9.72 |
| 2026-05-14 00:00 |
00:06:25.64 |
-29:53:37.9 |
HIP 477 |
10.08 |
| 2026-05-14 12:00 |
00:06:28.26 |
-29:54:01.1 |
HIP 477 |
10.46 |
| 2026-05-15 00:00 |
00:06:30.84 |
-29:54:24.8 |
HIP 477 |
10.87 |
| 2026-05-15 12:00 |
00:06:33.37 |
-29:54:49.0 |
HIP 477 |
11.28 |
| 2026-05-16 00:00 |
00:06:35.86 |
-29:55:13.7 |
HIP 477 |
11.71 |
| 2026-05-16 12:00 |
00:06:38.31 |
-29:55:38.8 |
HIP 477 |
12.16 |
| 2026-05-17 00:00 |
00:06:40.71 |
-29:56:04.5 |
HIP 477 |
12.61 |
| 2026-05-17 12:00 |
00:06:43.07 |
-29:56:30.6 |
HIP 477 |
13.07 |
| 2026-05-18 00:00 |
00:06:45.38 |
-29:56:57.2 |
HIP 477 |
13.54 |
| 2026-05-18 12:00 |
00:06:47.64 |
-29:57:24.3 |
HIP 477 |
14.01 |
| 2026-05-19 00:00 |
00:06:49.86 |
-29:57:51.9 |
HIP 477 |
14.49 |
| 2026-05-19 12:00 |
00:06:52.03 |
-29:58:20.0 |
HIP 477 |
14.98 |
| 2026-05-20 00:00 |
00:06:54.16 |
-29:58:48.5 |
HIP 653 |
14.99 |
| 2026-05-20 12:00 |
00:06:56.23 |
-29:59:17.5 |
HIP 653 |
14.45 |
| 2026-05-21 00:00 |
00:06:58.26 |
-29:59:47.0 |
HIP 653 |
13.93 |
| 2026-05-21 12:00 |
00:07:00.25 |
-30:00:16.9 |
HIP 653 |
13.44 |
| 2026-05-22 00:00 |
00:07:02.18 |
-30:00:47.4 |
HIP 653 |
12.97 |
| 2026-05-22 12:00 |
00:07:04.07 |
-30:01:18.3 |
HIP 653 |
12.53 |
| 2026-05-23 00:00 |
00:07:05.91 |
-30:01:49.6 |
HIP 653 |
12.12 |
| 2026-05-23 12:00 |
00:07:07.70 |
-30:02:21.5 |
HIP 653 |
11.74 |
| 2026-05-24 00:00 |
00:07:09.44 |
-30:02:53.8 |
HIP 653 |
11.39 |
| 2026-05-24 12:00 |
00:07:11.13 |
-30:03:26.5 |
HIP 653 |
11.09 |
| 2026-05-25 00:00 |
00:07:12.78 |
-30:03:59.8 |
HIP 653 |
10.83 |
| 2026-05-25 12:00 |
00:07:14.37 |
-30:04:33.5 |
HIP 653 |
10.62 |
| 2026-05-26 00:00 |
00:07:15.91 |
-30:05:07.6 |
HIP 653 |
10.46 |
| 2026-05-26 12:00 |
00:07:17.41 |
-30:05:42.2 |
HIP 653 |
10.35 |
| 2026-05-27 00:00 |
00:07:18.85 |
-30:06:17.3 |
HIP 653 |
10.29 |
| 2026-05-27 12:00 |
00:07:20.24 |
-30:06:52.8 |
HIP 653 |
10.29 |
| 2026-05-28 00:00 |
00:07:21.59 |
-30:07:28.7 |
HIP 653 |
10.35 |
| 2026-05-28 12:00 |
00:07:22.88 |
-30:08:05.1 |
HIP 653 |
10.46 |
| 2026-05-29 00:00 |
00:07:24.12 |
-30:08:42.0 |
HIP 653 |
10.63 |
| 2026-05-29 12:00 |
00:07:25.31 |
-30:09:19.3 |
HIP 653 |
10.85 |
| 2026-05-30 00:00 |
00:07:26.44 |
-30:09:57.0 |
HIP 653 |
11.12 |
| 2026-05-30 12:00 |
00:07:27.53 |
-30:10:35.2 |
HIP 653 |
11.43 |
| 2026-05-31 00:00 |
00:07:28.56 |
-30:11:13.9 |
HIP 653 |
11.79 |
| 2026-05-31 12:00 |
00:07:29.54 |
-30:11:53.0 |
HIP 653 |
12.19 |
| 2026-06-01 00:00 |
00:07:30.47 |
-30:12:32.5 |
HIP 653 |
12.62 |
| 2026-06-01 12:00 |
00:07:31.35 |
-30:13:12.4 |
HIP 653 |
13.09 |
| 2026-06-02 00:00 |
00:07:32.17 |
-30:13:52.8 |
HIP 653 |
13.59 |