メタデータ

項目	値
Designation	C/2010 X1 (Elenin)
Type	C
Perihelion (tp_cal, UTC)	2011-09-10T17:16:26.166720Z
Orbit solution date (soln_date, UTC)	2021-04-15T23:31:47Z
Obs used	2235
NEO	-
M1	12.600
K1	6.250
PC	-

オスキュレーティング軌道要素

項目	値
Epoch (epoch_cal, TDB)	2011-03-31.0000000
e	1.00006725
q (au)	0.482421
a (au)	-7173.388485
i (deg)	1.839568
Ω (om, deg)	323.235147
ω (w, deg)	343.798118
M (ma, deg)	-0.000266

等級

散乱 + 全体線形

$$ M_a = (12.212 + 2.745\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

モデル定数

項目	値
H0	12.212
n	2.745
gf	0.800
gb	-0.772
k	0.993
δ90	10.000

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
2010-12-10	2011-07-01	+1.4907	-0.743
2011-07-01	2011-08-03	+16.9717	-4.126
2011-08-03	2011-09-07	-9.5074	-4.344

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	07:34:32.73	+22:34:05.4	HIP 36853	13.89
2026-06-01 12:00	07:34:35.57	+22:33:58.4	HIP 36853	13.72
2026-06-02 00:00	07:34:38.43	+22:33:51.5	HIP 36853	13.59
2026-06-02 12:00	07:34:41.30	+22:33:44.5	HIP 36853	13.48
2026-06-03 00:00	07:34:44.19	+22:33:37.4	HIP 36853	13.41
2026-06-03 12:00	07:34:47.11	+22:33:30.3	HIP 36853	13.37
2026-06-04 00:00	07:34:50.04	+22:33:23.2	HIP 36853	13.36
2026-06-04 12:00	07:34:52.98	+22:33:16.0	HIP 36853	13.39
2026-06-05 00:00	07:34:55.95	+22:33:08.8	HIP 36853	13.46
2026-06-05 12:00	07:34:58.94	+22:33:01.6	HIP 36853	13.56
2026-06-06 00:00	07:35:01.94	+22:32:54.3	HIP 36853	13.70
2026-06-06 12:00	07:35:04.95	+22:32:47.0	HIP 36853	13.87
2026-06-07 00:00	07:35:07.99	+22:32:39.6	HIP 36853	14.08
2026-06-07 12:00	07:35:11.04	+22:32:32.3	HIP 36853	14.33
2026-06-08 00:00	07:35:14.11	+22:32:24.8	HIP 36853	14.60
2026-06-08 12:00	07:35:17.20	+22:32:17.4	HIP 36853	14.91
2026-06-09 00:00	07:35:20.30	+22:32:09.9	HIP 36853	15.25
2026-06-09 12:00	07:35:23.42	+22:32:02.4	HIP 36853	15.61
2026-06-10 00:00	07:35:26.55	+22:31:54.8	HIP 36853	16.01
2026-06-10 12:00	07:35:29.70	+22:31:47.2	HIP 36853	16.43
2026-06-11 00:00	07:35:32.87	+22:31:39.6	HIP 36853	16.87
2026-06-11 12:00	07:35:36.05	+22:31:31.9	HIP 36853	17.34
2026-06-12 00:00	07:35:39.24	+22:31:24.2	HIP 36853	17.82
2026-06-12 12:00	07:35:42.46	+22:31:16.5	HIP 36853	18.33
2026-06-13 00:00	07:35:45.68	+22:31:08.7	HIP 36853	18.86
2026-06-13 12:00	07:35:48.92	+22:31:00.9	HIP 36853	19.40
2026-06-14 00:00	07:35:52.17	+22:30:53.1	HIP 36853	19.96
2026-06-14 12:00	07:35:55.44	+22:30:45.3	HIP 36853	20.54
2026-06-15 00:00	07:35:58.72	+22:30:37.4	HIP 36853	21.13
2026-06-15 12:00	07:36:02.02	+22:30:29.5	HIP 36853	21.74
2026-06-16 00:00	07:36:05.33	+22:30:21.5	HIP 36853	22.36
2026-06-16 12:00	07:36:08.65	+22:30:13.6	HIP 36853	22.99
2026-06-17 00:00	07:36:11.98	+22:30:05.6	HIP 37121	22.56
2026-06-17 12:00	07:36:15.33	+22:29:57.6	HIP 37121	21.81
2026-06-18 00:00	07:36:18.69	+22:29:49.5	HIP 37121	21.05
2026-06-18 12:00	07:36:22.06	+22:29:41.4	HIP 37121	20.30
2026-06-19 00:00	07:36:25.44	+22:29:33.3	HIP 37121	19.54
2026-06-19 12:00	07:36:28.84	+22:29:25.2	HIP 37121	18.78
2026-06-20 00:00	07:36:32.24	+22:29:17.1	HIP 37121	18.03
2026-06-20 12:00	07:36:35.66	+22:29:08.9	HIP 37121	17.28
2026-06-21 00:00	07:36:39.09	+22:29:00.7	HIP 37121	16.53
2026-06-21 12:00	07:36:42.53	+22:28:52.5	HIP 37121	15.78
2026-06-22 00:00	07:36:45.98	+22:28:44.3	HIP 37121	15.04