C/2015 XY1 (Lemmon)

メタデータ

項目
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
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

C/2015 XY1 (Lemmon) · Magnitude (Full range)

散乱 + 全体線形

$$ M_a = (-0.855 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

モデル定数

項目
H0 -0.855
n 6.000
gf 0.882
gb -0.939
k 1.000
δ90 3.868
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)
2026-07-29 00:00 00:02:43.98 -32:05:28.8 HIP 104 21.48
2026-07-29 12:00 00:02:38.08 -32:06:36.9 HIP 104 21.09
2026-07-30 00:00 00:02:32.12 -32:07:44.9 HIP 104 20.83
2026-07-30 12:00 00:02:26.11 -32:08:52.9 HIP 104 20.69
2026-07-31 00:00 00:02:20.05 -32:10:00.9 HIP 104 20.68
2026-07-31 12:00 00:02:13.93 -32:11:08.8 HIP 104 20.81
2026-08-01 00:00 00:02:07.76 -32:12:16.7 HIP 104 21.08
2026-08-01 12:00 00:02:01.54 -32:13:24.5 HIP 104 21.47
2026-08-02 00:00 00:01:55.27 -32:14:32.3 HIP 104 21.99
2026-08-02 12:00 00:01:48.95 -32:15:40.0 HIP 104 22.63
2026-08-03 00:00 00:01:42.57 -32:16:47.6 HIP 104 23.38
2026-08-03 12:00 00:01:36.14 -32:17:55.2 HIP 118304 24.15
2026-08-04 00:00 00:01:29.66 -32:19:02.7 HIP 118304 23.10
2026-08-04 12:00 00:01:23.14 -32:20:10.1 HIP 118304 22.14
2026-08-05 00:00 00:01:16.56 -32:21:17.4 HIP 118304 21.26
2026-08-05 12:00 00:01:09.93 -32:22:24.6 HIP 118304 20.50
2026-08-06 00:00 00:01:03.25 -32:23:31.7 HIP 118304 19.86
2026-08-06 12:00 00:00:56.53 -32:24:38.7 HIP 118304 19.36
2026-08-07 00:00 00:00:49.75 -32:25:45.6 HIP 118304 19.01
2026-08-07 12:00 00:00:42.93 -32:26:52.4 HIP 118304 18.82
2026-08-08 00:00 00:00:36.05 -32:27:59.1 HIP 118304 18.80
2026-08-08 12:00 00:00:29.13 -32:29:05.6 HIP 94 18.52
2026-08-09 00:00 00:00:22.17 -32:30:12.0 HIP 94 18.33
2026-08-09 12:00 00:00:15.15 -32:31:18.3 HIP 94 18.33
2026-08-10 00:00 00:00:08.09 -32:32:24.4 HIP 94 18.52
2026-08-10 12:00 00:00:00.98 -32:33:30.3 HIP 94 18.90
2026-08-11 00:00 23:59:53.83 -32:34:36.1 HIP 94 19.47
2026-08-11 12:00 23:59:46.63 -32:35:41.8 HIP 94 20.19
2026-08-12 00:00 23:59:39.39 -32:36:47.2 HIP 94 21.07
2026-08-12 12:00 23:59:32.10 -32:37:52.5 HIP 94 22.08
2026-08-13 00:00 23:59:24.77 -32:38:57.6 HIP 94 23.21
2026-08-13 12:00 23:59:17.39 -32:40:02.5 HIP 94 24.44
2026-08-14 00:00 23:59:09.98 -32:41:07.3 HIP 94 25.76
2026-08-14 12:00 23:59:02.51 -32:42:11.8 HIP 94 27.16
2026-08-15 00:00 23:58:55.01 -32:43:16.1 HIP 118165 26.52
2026-08-15 12:00 23:58:47.47 -32:44:20.2 HIP 118165 24.97
2026-08-16 00:00 23:58:39.88 -32:45:24.1 HIP 118165 23.47
2026-08-16 12:00 23:58:32.25 -32:46:27.8 HIP 118165 22.04
2026-08-17 00:00 23:58:24.59 -32:47:31.2 HIP 118165 20.69
2026-08-17 12:00 23:58:16.88 -32:48:34.5 HIP 118165 19.44
2026-08-18 00:00 23:58:09.14 -32:49:37.4 HIP 118165 18.31
2026-08-18 12:00 23:58:01.36 -32:50:40.2 HIP 118165 17.33
2026-08-19 00:00 23:57:53.53 -32:51:42.6 HIP 118165 16.52