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)
2026-07-29 00:00	09:06:20.55	-06:37:08.1	HIP 44701	38.25
2026-07-29 12:00	09:06:37.79	-06:38:06.7	HIP 44804	35.45
2026-07-30 00:00	09:06:55.02	-06:39:05.9	HIP 44804	32.53
2026-07-30 12:00	09:07:12.26	-06:40:05.9	HIP 44804	29.95
2026-07-31 00:00	09:07:29.51	-06:41:06.5	HIP 44804	27.82
2026-07-31 12:00	09:07:46.75	-06:42:07.7	HIP 44804	26.24
2026-08-01 00:00	09:08:03.99	-06:43:09.7	HIP 44804	25.33
2026-08-01 12:00	09:08:21.24	-06:44:12.2	HIP 44804	25.16
2026-08-02 00:00	09:08:38.48	-06:45:15.5	HIP 44804	25.74
2026-08-02 12:00	09:08:55.72	-06:46:19.4	HIP 44804	27.03
2026-08-03 00:00	09:09:12.96	-06:47:24.0	HIP 44804	28.93
2026-08-03 12:00	09:09:30.20	-06:48:29.2	HIP 44804	31.34
2026-08-04 00:00	09:09:47.44	-06:49:35.0	HIP 45143	32.09
2026-08-04 12:00	09:10:04.67	-06:50:41.5	HIP 45143	27.67
2026-08-05 00:00	09:10:21.90	-06:51:48.7	HIP 45143	23.26
2026-08-05 12:00	09:10:39.12	-06:52:56.5	HIP 45143	18.84
2026-08-06 00:00	09:10:56.34	-06:54:04.9	HIP 45143	14.43
2026-08-06 12:00	09:11:13.55	-06:55:14.0	HIP 45143	10.02
2026-08-07 00:00	09:11:30.76	-06:56:23.7	HIP 45143	5.63
2026-08-07 12:00	09:11:47.96	-06:57:34.0	HIP 45143	1.47
2026-08-08 00:00	09:12:05.16	-06:58:44.9	HIP 45143	3.44
2026-08-08 12:00	09:12:22.34	-06:59:56.5	HIP 45180	4.17
2026-08-09 00:00	09:12:39.52	-07:01:08.7	HIP 45180	6.38
2026-08-09 12:00	09:12:56.69	-07:02:21.6	HIP 45184	8.70
2026-08-10 00:00	09:13:13.85	-07:03:35.0	HIP 45184	12.23
2026-08-10 12:00	09:13:31.00	-07:04:49.1	HIP 45184	16.21
2026-08-11 00:00	09:13:48.14	-07:06:03.8	HIP 45184	20.37
2026-08-11 12:00	09:14:05.27	-07:07:19.1	HIP 45184	24.62
2026-08-12 00:00	09:14:22.39	-07:08:35.0	HIP 45184	28.93
2026-08-12 12:00	09:14:39.49	-07:09:51.4	HIP 45184	33.26
2026-08-13 00:00	09:14:56.58	-07:11:08.5	HIP 45228	35.94
2026-08-13 12:00	09:15:13.66	-07:12:26.2	HIP 45530	36.88
2026-08-14 00:00	09:15:30.72	-07:13:44.5	HIP 45596	34.10
2026-08-14 12:00	09:15:47.76	-07:15:03.3	HIP 45596	29.71
2026-08-15 00:00	09:16:04.79	-07:16:22.8	HIP 45596	25.33
2026-08-15 12:00	09:16:21.81	-07:17:42.8	HIP 45596	20.98
2026-08-16 00:00	09:16:38.80	-07:19:03.4	HIP 45596	16.65
2026-08-16 12:00	09:16:55.78	-07:20:24.6	HIP 45596	12.40
2026-08-17 00:00	09:17:12.74	-07:21:46.3	HIP 45596	8.33
2026-08-17 12:00	09:17:29.68	-07:23:08.6	HIP 45596	4.89
2026-08-18 00:00	09:17:46.60	-07:24:31.4	HIP 45596	4.17
2026-08-18 12:00	09:18:03.51	-07:25:54.9	HIP 45596	7.06
2026-08-19 00:00	09:18:20.39	-07:27:18.8	HIP 45596	11.00