メタデータ

項目	値
Designation	C/2013 C2 (Tenagra)
Type	C
Perihelion (tp_cal, UTC)	2015-09-02T03:56:21.143040Z
Orbit solution date (soln_date, UTC)	2026-03-07T14:42:52Z
Obs used	550
NEO	-
M1	9.400
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)	2016-07-16.0000000
e	0.43171756
q (au)	9.131701
a (au)	16.068948
i (deg)	21.336708
Ω (om, deg)	247.531370
ω (w, deg)	308.907427
M (ma, deg)	4.863241

等級

散乱 + 全体線形

$$ M_a = (9.703 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

モデル定数

項目	値
H0	9.703
n	2.000
gf	1.000
gb	-0.509
k	0.800
δ90	8.721

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
2015-12-18	2019-05-05	+33.7951	-32.588
2019-05-05	2025-11-17	-18.1492	+19.881

log10 r = log10(太陽距離/AU)、Δ = 地球距離(AU)

ファインディングチャート

天体暦

Date/Time (UTC)	RA (J2000)	Dec (J2000)	Nearest HIP	Dist from HIP (arcmin)
2026-06-01 00:00	20:26:11.68	+00:24:56.8	HIP 100590	35.31
2026-06-01 12:00	20:26:08.88	+00:25:25.0	HIP 100590	34.53
2026-06-02 00:00	20:26:06.02	+00:25:52.8	HIP 100590	33.75
2026-06-02 12:00	20:26:03.12	+00:26:20.2	HIP 100590	32.96
2026-06-03 00:00	20:26:00.15	+00:26:47.3	HIP 100590	32.16
2026-06-03 12:00	20:25:57.14	+00:27:14.0	HIP 100590	31.36
2026-06-04 00:00	20:25:54.07	+00:27:40.4	HIP 100590	30.54
2026-06-04 12:00	20:25:50.95	+00:28:06.4	HIP 100590	29.72
2026-06-05 00:00	20:25:47.78	+00:28:32.0	HIP 100590	28.88
2026-06-05 12:00	20:25:44.55	+00:28:57.3	HIP 100590	28.04
2026-06-06 00:00	20:25:41.27	+00:29:22.2	HIP 100590	27.19
2026-06-06 12:00	20:25:37.94	+00:29:46.7	HIP 100590	26.33
2026-06-07 00:00	20:25:34.56	+00:30:10.8	HIP 100590	25.47
2026-06-07 12:00	20:25:31.13	+00:30:34.6	HIP 100590	24.60
2026-06-08 00:00	20:25:27.65	+00:30:58.0	HIP 100590	23.72
2026-06-08 12:00	20:25:24.12	+00:31:21.1	HIP 100590	22.83
2026-06-09 00:00	20:25:20.53	+00:31:43.7	HIP 100590	21.94
2026-06-09 12:00	20:25:16.90	+00:32:06.0	HIP 100590	21.04
2026-06-10 00:00	20:25:13.22	+00:32:27.9	HIP 100590	20.14
2026-06-10 12:00	20:25:09.49	+00:32:49.4	HIP 100590	19.23
2026-06-11 00:00	20:25:05.71	+00:33:10.5	HIP 100590	18.32
2026-06-11 12:00	20:25:01.88	+00:33:31.2	HIP 100590	17.41
2026-06-12 00:00	20:24:58.00	+00:33:51.6	HIP 100590	16.49
2026-06-12 12:00	20:24:54.08	+00:34:11.5	HIP 100590	15.58
2026-06-13 00:00	20:24:50.11	+00:34:31.1	HIP 100590	14.67
2026-06-13 12:00	20:24:46.09	+00:34:50.2	HIP 100590	13.77
2026-06-14 00:00	20:24:42.02	+00:35:09.0	HIP 100590	12.88
2026-06-14 12:00	20:24:37.91	+00:35:27.4	HIP 100590	12.00
2026-06-15 00:00	20:24:33.76	+00:35:45.4	HIP 100590	11.15
2026-06-15 12:00	20:24:29.55	+00:36:03.0	HIP 100590	10.32
2026-06-16 00:00	20:24:25.31	+00:36:20.2	HIP 100590	9.53
2026-06-16 12:00	20:24:21.02	+00:36:37.0	HIP 100590	8.80
2026-06-17 00:00	20:24:16.68	+00:36:53.4	HIP 100590	8.14
2026-06-17 12:00	20:24:12.30	+00:37:09.3	HIP 100590	7.58
2026-06-18 00:00	20:24:07.88	+00:37:24.9	HIP 100590	7.14
2026-06-18 12:00	20:24:03.42	+00:37:40.1	HIP 100590	6.85
2026-06-19 00:00	20:23:58.92	+00:37:54.9	HIP 100590	6.74
2026-06-19 12:00	20:23:54.37	+00:38:09.3	HIP 100590	6.81
2026-06-20 00:00	20:23:49.79	+00:38:23.3	HIP 100590	7.08
2026-06-20 12:00	20:23:45.16	+00:38:36.9	HIP 100590	7.51
2026-06-21 00:00	20:23:40.49	+00:38:50.0	HIP 100590	8.09
2026-06-21 12:00	20:23:35.79	+00:39:02.8	HIP 100590	8.79
2026-06-22 00:00	20:23:31.05	+00:39:15.2	HIP 100590	9.59