メタデータ

項目	値
Designation	272P/NEAT
Type	P
Perihelion (tp_cal, UTC)	2013-03-01T17:20:56.927040Z
Orbit solution date (soln_date, UTC)	2023-02-22T00:13:19Z
Obs used	189
NEO	-
M1	10.700
K1	18.500
PC	0.030

オスキュレーティング軌道要素

項目	値
Epoch (epoch_cal, TDB)	2010-04-10.0000000
e	0.45652880
q (au)	2.416276
a (au)	4.446005
i (deg)	18.188178
Ω (om, deg)	111.515253
ω (w, deg)	26.202307
M (ma, deg)	248.900968

等級

散乱 + 全体線形

$$ M_a = (16.618 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

モデル定数

項目	値
H0	16.618
n	2.000
gf	1.000
gb	-1.000
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)
2026-03-26 00:00	20:43:51.44	-21:24:52.0	HIP 102332	4.15
2026-03-26 12:00	20:44:07.12	-21:24:29.8	HIP 102332	3.53
2026-03-27 00:00	20:44:22.70	-21:24:08.0	HIP 102332	5.87
2026-03-27 12:00	20:44:38.17	-21:23:46.7	HIP 102332	9.08
2026-03-28 00:00	20:44:53.54	-21:23:25.8	HIP 102332	12.50
2026-03-28 12:00	20:45:08.81	-21:23:05.3	HIP 102332	15.97
2026-03-29 00:00	20:45:23.96	-21:22:45.4	HIP 102487	13.42
2026-03-29 12:00	20:45:39.02	-21:22:25.8	HIP 102487	11.07
2026-03-30 00:00	20:45:53.96	-21:22:06.8	HIP 102487	9.49
2026-03-30 12:00	20:46:08.80	-21:21:48.1	HIP 102487	9.04
2026-03-31 00:00	20:46:23.53	-21:21:30.0	HIP 102487	9.86
2026-03-31 12:00	20:46:38.14	-21:21:12.3	HIP 102487	11.65
2026-04-01 00:00	20:46:52.65	-21:20:55.1	HIP 102487	14.04
2026-04-01 12:00	20:47:07.05	-21:20:38.4	HIP 102487	16.75
2026-04-02 00:00	20:47:21.34	-21:20:22.2	HIP 102487	19.63
2026-04-02 12:00	20:47:35.52	-21:20:06.5	HIP 102487	22.62
2026-04-03 00:00	20:47:49.59	-21:19:51.2	HIP 102743	25.50
2026-04-03 12:00	20:48:03.54	-21:19:36.5	HIP 102743	23.53
2026-04-04 00:00	20:48:17.38	-21:19:22.2	HIP 102743	21.87
2026-04-04 12:00	20:48:31.11	-21:19:08.5	HIP 102743	20.58
2026-04-05 00:00	20:48:44.72	-21:18:55.3	HIP 102743	19.74
2026-04-05 12:00	20:48:58.21	-21:18:42.6	HIP 102743	19.38
2026-04-06 00:00	20:49:11.59	-21:18:30.4	HIP 102743	19.52
2026-04-06 12:00	20:49:24.85	-21:18:18.7	HIP 102743	20.13
2026-04-07 00:00	20:49:38.00	-21:18:07.6	HIP 102908	17.74
2026-04-07 12:00	20:49:51.03	-21:17:57.0	HIP 102908	14.72
2026-04-08 00:00	20:50:03.94	-21:17:46.9	HIP 102908	11.73
2026-04-08 12:00	20:50:16.72	-21:17:37.4	HIP 102908	8.79
2026-04-09 00:00	20:50:29.39	-21:17:28.4	HIP 102908	5.90
2026-04-09 12:00	20:50:41.94	-21:17:20.0	HIP 102908	3.17
2026-04-10 00:00	20:50:54.36	-21:17:12.1	HIP 102908	1.53
2026-04-10 12:00	20:51:06.67	-21:17:04.8	HIP 102908	3.35
2026-04-11 00:00	20:51:18.85	-21:16:58.0	HIP 102908	6.02
2026-04-11 12:00	20:51:30.90	-21:16:51.8	HIP 102908	8.76
2026-04-12 00:00	20:51:42.83	-21:16:46.2	HIP 103027	9.49
2026-04-12 12:00	20:51:54.64	-21:16:41.2	HIP 103027	6.89
2026-04-13 00:00	20:52:06.32	-21:16:36.8	HIP 103027	4.50
2026-04-13 12:00	20:52:17.87	-21:16:32.9	HIP 103027	2.83
2026-04-14 00:00	20:52:29.30	-21:16:29.7	HIP 103027	3.19
2026-04-14 12:00	20:52:40.59	-21:16:27.0	HIP 103027	5.13
2026-04-15 00:00	20:52:51.76	-21:16:24.9	HIP 103027	7.48
2026-04-15 12:00	20:53:02.80	-21:16:23.4	HIP 103027	9.93
2026-04-16 00:00	20:53:13.71	-21:16:22.6	HIP 103027	12.40