メタデータ

項目	値
Designation	255P/Levy
Type	P
Perihelion (tp_cal, UTC)	2006-10-07T09:13:57.613440Z
Orbit solution date (soln_date, UTC)	2021-10-18T22:42:54Z
Obs used	503
NEO	Yes
M1	11.500
K1	38.000
PC	0.030

オスキュレーティング軌道要素

項目	値
Epoch (epoch_cal, TDB)	2007-12-22.0000000
e	0.67200978
q (au)	0.992018
a (au)	3.024534
i (deg)	18.333043
Ω (om, deg)	279.780048
ω (w, deg)	179.592955
M (ma, deg)	82.561191

等級

散乱 + 全体線形

$$ M_a = (20.000 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

モデル定数

項目	値
H0	20.000
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

天体暦

Date/Time (UTC)	RA (J2000)	Dec (J2000)	Nearest HIP	Dist from HIP (arcmin)
2026-05-12 00:00	21:08:28.48	-09:36:00.2	HIP 104331	26.71
2026-05-12 12:00	21:08:34.31	-09:34:19.1	HIP 104331	25.45
2026-05-13 00:00	21:08:39.92	-09:32:38.7	HIP 104331	24.32
2026-05-13 12:00	21:08:45.33	-09:30:58.9	HIP 104331	23.32
2026-05-14 00:00	21:08:50.52	-09:29:19.8	HIP 104331	22.46
2026-05-14 12:00	21:08:55.51	-09:27:41.2	HIP 104331	21.75
2026-05-15 00:00	21:09:00.28	-09:26:03.4	HIP 104331	21.19
2026-05-15 12:00	21:09:04.84	-09:24:26.1	HIP 104331	20.78
2026-05-16 00:00	21:09:09.18	-09:22:49.5	HIP 104331	20.52
2026-05-16 12:00	21:09:13.31	-09:21:13.6	HIP 104331	20.40
2026-05-17 00:00	21:09:17.22	-09:19:38.4	HIP 104331	20.41
2026-05-17 12:00	21:09:20.92	-09:18:03.9	HIP 104331	20.55
2026-05-18 00:00	21:09:24.39	-09:16:30.0	HIP 104331	20.80
2026-05-18 12:00	21:09:27.64	-09:14:56.9	HIP 104557	20.53
2026-05-19 00:00	21:09:30.68	-09:13:24.4	HIP 104557	20.36
2026-05-19 12:00	21:09:33.49	-09:11:52.7	HIP 104557	20.38
2026-05-20 00:00	21:09:36.07	-09:10:21.7	HIP 104557	20.58
2026-05-20 12:00	21:09:38.44	-09:08:51.4	HIP 104557	20.94
2026-05-21 00:00	21:09:40.57	-09:07:21.9	HIP 104557	21.45
2026-05-21 12:00	21:09:42.49	-09:05:53.1	HIP 104557	22.09
2026-05-22 00:00	21:09:44.17	-09:04:25.1	HIP 104557	22.85
2026-05-22 12:00	21:09:45.63	-09:02:57.8	HIP 104557	23.71
2026-05-23 00:00	21:09:46.86	-09:01:31.3	HIP 104557	24.66
2026-05-23 12:00	21:09:47.86	-09:00:05.6	HIP 104557	25.67
2026-05-24 00:00	21:09:48.63	-08:58:40.6	HIP 104557	26.75
2026-05-24 12:00	21:09:49.17	-08:57:16.4	HIP 104557	27.87
2026-05-25 00:00	21:09:49.47	-08:55:53.1	HIP 104557	29.04
2026-05-25 12:00	21:09:49.55	-08:54:30.5	HIP 104331	30.21
2026-05-26 00:00	21:09:49.39	-08:53:08.7	HIP 104331	30.90
2026-05-26 12:00	21:09:48.99	-08:51:47.8	HIP 104331	31.58
2026-05-27 00:00	21:09:48.36	-08:50:27.6	HIP 104331	32.24
2026-05-27 12:00	21:09:47.50	-08:49:08.3	HIP 104331	32.89
2026-05-28 00:00	21:09:46.39	-08:47:49.9	HIP 104331	33.53
2026-05-28 12:00	21:09:45.05	-08:46:32.2	HIP 104331	34.16
2026-05-29 00:00	21:09:43.47	-08:45:15.5	HIP 104331	34.77
2026-05-29 12:00	21:09:41.65	-08:43:59.6	HIP 104300	33.77
2026-05-30 00:00	21:09:39.59	-08:42:44.5	HIP 104300	32.68
2026-05-30 12:00	21:09:37.29	-08:41:30.3	HIP 104300	31.57
2026-05-31 00:00	21:09:34.74	-08:40:17.0	HIP 104300	30.42
2026-05-31 12:00	21:09:31.96	-08:39:04.6	HIP 104300	29.25
2026-06-01 00:00	21:09:28.92	-08:37:53.1	HIP 104300	28.05
2026-06-01 12:00	21:09:25.65	-08:36:42.5	HIP 104300	26.83
2026-06-02 00:00	21:09:22.12	-08:35:32.8	HIP 104300	25.57