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)
2026-09-20 00:00	09:35:12.92	-09:13:18.1	HIP 46875	31.36
2026-09-20 12:00	09:35:27.27	-09:15:10.1	HIP 46875	34.59
2026-09-21 00:00	09:35:41.56	-09:17:02.5	HIP 47249	33.15
2026-09-21 12:00	09:35:55.79	-09:18:55.1	HIP 47249	29.29
2026-09-22 00:00	09:36:09.97	-09:20:48.0	HIP 47249	25.49
2026-09-22 12:00	09:36:24.08	-09:22:41.2	HIP 47249	21.75
2026-09-23 00:00	09:36:38.13	-09:24:34.7	HIP 47249	18.13
2026-09-23 12:00	09:36:52.12	-09:26:28.4	HIP 47249	14.69
2026-09-24 00:00	09:37:06.05	-09:28:22.4	HIP 47249	11.59
2026-09-24 12:00	09:37:19.92	-09:30:16.7	HIP 47249	9.16
2026-09-25 00:00	09:37:33.73	-09:32:11.2	HIP 47249	8.03
2026-09-25 12:00	09:37:47.47	-09:34:06.0	HIP 47249	8.69
2026-09-26 00:00	09:38:01.15	-09:36:01.0	HIP 47249	10.81
2026-09-26 12:00	09:38:14.76	-09:37:56.3	HIP 47249	13.72
2026-09-27 00:00	09:38:28.31	-09:39:51.8	HIP 47249	17.01
2026-09-27 12:00	09:38:41.80	-09:41:47.6	HIP 47249	20.49
2026-09-28 00:00	09:38:55.22	-09:43:43.6	HIP 47249	24.08
2026-09-28 12:00	09:39:08.57	-09:45:39.8	HIP 47249	27.72
2026-09-29 00:00	09:39:21.86	-09:47:36.2	HIP 47249	31.39
2026-09-29 12:00	09:39:35.08	-09:49:32.9	HIP 47249	35.09
2026-09-30 00:00	09:39:48.23	-09:51:29.8	HIP 47249	38.79
2026-09-30 12:00	09:40:01.31	-09:53:26.9	HIP 47427	40.91
2026-10-01 00:00	09:40:14.32	-09:55:24.2	HIP 47534	39.14
2026-10-01 12:00	09:40:27.27	-09:57:21.7	HIP 47534	35.99
2026-10-02 00:00	09:40:40.14	-09:59:19.4	HIP 47534	32.96
2026-10-02 12:00	09:40:52.94	-10:01:17.3	HIP 47534	30.09
2026-10-03 00:00	09:41:05.67	-10:03:15.4	HIP 47534	27.43
2026-10-03 12:00	09:41:18.33	-10:05:13.7	HIP 47534	25.03
2026-10-04 00:00	09:41:30.92	-10:07:12.1	HIP 47534	22.97
2026-10-04 12:00	09:41:43.43	-10:09:10.8	HIP 47534	21.33
2026-10-05 00:00	09:41:55.87	-10:11:09.6	HIP 47534	20.23
2026-10-05 12:00	09:42:08.23	-10:13:08.5	HIP 47534	19.74
2026-10-06 00:00	09:42:20.52	-10:15:07.7	HIP 47534	19.89
2026-10-06 12:00	09:42:32.73	-10:17:06.9	HIP 47534	20.66
2026-10-07 00:00	09:42:44.86	-10:19:06.4	HIP 47534	21.99
2026-10-07 12:00	09:42:56.92	-10:21:05.9	HIP 47534	23.77
2026-10-08 00:00	09:43:08.90	-10:23:05.6	HIP 47734	25.62
2026-10-08 12:00	09:43:20.80	-10:25:05.4	HIP 47734	26.56
2026-10-09 00:00	09:43:32.62	-10:27:05.4	HIP 47734	27.92
2026-10-09 12:00	09:43:44.36	-10:29:05.5	HIP 47621	28.73
2026-10-10 00:00	09:43:56.02	-10:31:05.6	HIP 47621	28.90
2026-10-10 12:00	09:44:07.59	-10:33:05.9	HIP 47621	29.46
2026-10-11 00:00	09:44:19.09	-10:35:06.3	HIP 47621	30.40