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)
2026-03-26 00:00	07:32:09.62	+22:41:10.9	HIP 36708	14.50
2026-03-26 12:00	07:32:08.63	+22:41:12.2	HIP 36708	14.70
2026-03-27 00:00	07:32:07.68	+22:41:13.4	HIP 36708	14.90
2026-03-27 12:00	07:32:06.76	+22:41:14.5	HIP 36708	15.09
2026-03-28 00:00	07:32:05.87	+22:41:15.5	HIP 36708	15.28
2026-03-28 12:00	07:32:05.01	+22:41:16.5	HIP 36708	15.45
2026-03-29 00:00	07:32:04.18	+22:41:17.4	HIP 36708	15.63
2026-03-29 12:00	07:32:03.39	+22:41:18.2	HIP 36708	15.79
2026-03-30 00:00	07:32:02.63	+22:41:19.0	HIP 36708	15.95
2026-03-30 12:00	07:32:01.91	+22:41:19.6	HIP 36708	16.10
2026-03-31 00:00	07:32:01.21	+22:41:20.2	HIP 36708	16.24
2026-03-31 12:00	07:32:00.55	+22:41:20.8	HIP 36708	16.38
2026-04-01 00:00	07:31:59.92	+22:41:21.2	HIP 36708	16.51
2026-04-01 12:00	07:31:59.33	+22:41:21.6	HIP 36708	16.63
2026-04-02 00:00	07:31:58.77	+22:41:21.9	HIP 36691	16.73
2026-04-02 12:00	07:31:58.24	+22:41:22.2	HIP 36691	16.82
2026-04-03 00:00	07:31:57.74	+22:41:22.3	HIP 36691	16.90
2026-04-03 12:00	07:31:57.27	+22:41:22.4	HIP 36691	16.97
2026-04-04 00:00	07:31:56.84	+22:41:22.5	HIP 36691	17.05
2026-04-04 12:00	07:31:56.44	+22:41:22.4	HIP 36691	17.11
2026-04-05 00:00	07:31:56.08	+22:41:22.3	HIP 36691	17.18
2026-04-05 12:00	07:31:55.75	+22:41:22.1	HIP 36691	17.23
2026-04-06 00:00	07:31:55.44	+22:41:21.8	HIP 36691	17.29
2026-04-06 12:00	07:31:55.18	+22:41:21.5	HIP 36691	17.34
2026-04-07 00:00	07:31:54.94	+22:41:21.1	HIP 36691	17.38
2026-04-07 12:00	07:31:54.74	+22:41:20.6	HIP 36691	17.42
2026-04-08 00:00	07:31:54.57	+22:41:20.1	HIP 36691	17.46
2026-04-08 12:00	07:31:54.44	+22:41:19.5	HIP 36691	17.49
2026-04-09 00:00	07:31:54.33	+22:41:18.8	HIP 36691	17.51
2026-04-09 12:00	07:31:54.26	+22:41:18.0	HIP 36691	17.53
2026-04-10 00:00	07:31:54.22	+22:41:17.2	HIP 36691	17.55
2026-04-10 12:00	07:31:54.22	+22:41:16.3	HIP 36691	17.56
2026-04-11 00:00	07:31:54.25	+22:41:15.3	HIP 36691	17.57
2026-04-11 12:00	07:31:54.31	+22:41:14.3	HIP 36691	17.57
2026-04-12 00:00	07:31:54.40	+22:41:13.2	HIP 36691	17.56
2026-04-12 12:00	07:31:54.52	+22:41:12.0	HIP 36708	17.54
2026-04-13 00:00	07:31:54.68	+22:41:10.8	HIP 36708	17.50
2026-04-13 12:00	07:31:54.87	+22:41:09.4	HIP 36708	17.45
2026-04-14 00:00	07:31:55.10	+22:41:08.1	HIP 36708	17.40
2026-04-14 12:00	07:31:55.35	+22:41:06.6	HIP 36708	17.33
2026-04-15 00:00	07:31:55.64	+22:41:05.1	HIP 36708	17.26
2026-04-15 12:00	07:31:55.96	+22:41:03.5	HIP 36708	17.18
2026-04-16 00:00	07:31:56.31	+22:41:01.8	HIP 36708	17.10