メタデータ

項目	値
Designation	465P/Hill
Type	P
Perihelion (tp_cal, UTC)	2008-08-18T17:57:24.065280Z
Orbit solution date (soln_date, UTC)	2024-07-13T19:12:23Z
Obs used	706
NEO	-
M1	6.900
K1	25.250
PC	0.030

オスキュレーティング軌道要素

項目	値
Epoch (epoch_cal, TDB)	2011-07-24.0000000
e	0.61380782
q (au)	2.322142
a (au)	6.012919
i (deg)	25.854343
Ω (om, deg)	217.938849
ω (w, deg)	141.510289
M (ma, deg)	71.475305

等級

散乱 + 全体線形

$$ M_a = (10.276 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

モデル定数

項目	値
H0	10.276
n	6.000
gf	1.000
gb	-0.500
k	1.000
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
2023-06-08	2024-01-05	+9.7551	-4.150

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	08:23:49.43	-09:29:42.2	HIP 41051	18.07
2026-03-26 12:00	08:23:45.99	-09:27:35.3	HIP 41051	17.44
2026-03-27 00:00	08:23:42.69	-09:25:28.6	HIP 41051	17.13
2026-03-27 12:00	08:23:39.54	-09:23:22.1	HIP 41051	17.15
2026-03-28 00:00	08:23:36.54	-09:21:15.8	HIP 41051	17.49
2026-03-28 12:00	08:23:33.69	-09:19:09.8	HIP 41051	18.13
2026-03-29 00:00	08:23:30.99	-09:17:04.0	HIP 41051	19.02
2026-03-29 12:00	08:23:28.43	-09:14:58.4	HIP 41021	19.49
2026-03-30 00:00	08:23:26.02	-09:12:53.2	HIP 41021	18.21
2026-03-30 12:00	08:23:23.76	-09:10:48.2	HIP 41021	17.15
2026-03-31 00:00	08:23:21.65	-09:08:43.5	HIP 41021	16.34
2026-03-31 12:00	08:23:19.68	-09:06:39.1	HIP 41021	15.82
2026-04-01 00:00	08:23:17.87	-09:04:35.0	HIP 41021	15.60
2026-04-01 12:00	08:23:16.20	-09:02:31.2	HIP 41021	15.71
2026-04-02 00:00	08:23:14.67	-09:00:27.8	HIP 41021	16.12
2026-04-02 12:00	08:23:13.30	-08:58:24.7	HIP 41021	16.82
2026-04-03 00:00	08:23:12.07	-08:56:22.0	HIP 41021	17.75
2026-04-03 12:00	08:23:10.98	-08:54:19.6	HIP 41021	18.89
2026-04-04 00:00	08:23:10.05	-08:52:17.6	HIP 41021	20.20
2026-04-04 12:00	08:23:09.26	-08:50:16.0	HIP 41021	21.63
2026-04-05 00:00	08:23:08.61	-08:48:14.8	HIP 41155	22.54
2026-04-05 12:00	08:23:08.11	-08:46:14.0	HIP 41155	20.82
2026-04-06 00:00	08:23:07.76	-08:44:13.6	HIP 41155	19.15
2026-04-06 12:00	08:23:07.56	-08:42:13.6	HIP 41155	17.53
2026-04-07 00:00	08:23:07.49	-08:40:14.1	HIP 41155	15.98
2026-04-07 12:00	08:23:07.58	-08:38:15.0	HIP 41155	14.51
2026-04-08 00:00	08:23:07.81	-08:36:16.4	HIP 41155	13.16
2026-04-08 12:00	08:23:08.18	-08:34:18.2	HIP 41155	11.96
2026-04-09 00:00	08:23:08.70	-08:32:20.5	HIP 41155	10.96
2026-04-09 12:00	08:23:09.36	-08:30:23.3	HIP 41155	10.20
2026-04-10 00:00	08:23:10.17	-08:28:26.5	HIP 41155	9.75
2026-04-10 12:00	08:23:11.12	-08:26:30.3	HIP 41155	9.65
2026-04-11 00:00	08:23:12.21	-08:24:34.6	HIP 41155	9.90
2026-04-11 12:00	08:23:13.45	-08:22:39.4	HIP 41155	10.47
2026-04-12 00:00	08:23:14.82	-08:20:44.7	HIP 41155	11.32
2026-04-12 12:00	08:23:16.35	-08:18:50.6	HIP 41155	12.39
2026-04-13 00:00	08:23:18.01	-08:16:57.0	HIP 41155	13.62
2026-04-13 12:00	08:23:19.82	-08:15:03.9	HIP 41155	14.98
2026-04-14 00:00	08:23:21.76	-08:13:11.4	HIP 41155	16.43
2026-04-14 12:00	08:23:23.85	-08:11:19.5	HIP 41155	17.95
2026-04-15 00:00	08:23:26.08	-08:09:28.2	HIP 41155	19.53
2026-04-15 12:00	08:23:28.46	-08:07:37.5	HIP 41155	21.14
2026-04-16 00:00	08:23:30.97	-08:05:47.3	HIP 41155	22.79