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)
2026-07-29 00:00	20:37:56.76	-24:50:17.0	HIP 101808	16.30
2026-07-29 12:00	20:37:40.82	-24:51:43.2	HIP 101808	15.05
2026-07-30 00:00	20:37:24.87	-24:53:08.9	HIP 101808	14.76
2026-07-30 12:00	20:37:08.91	-24:54:34.3	HIP 101808	15.48
2026-07-31 00:00	20:36:52.95	-24:55:59.2	HIP 101808	17.08
2026-07-31 12:00	20:36:37.00	-24:57:23.6	HIP 101808	19.34
2026-08-01 00:00	20:36:21.04	-24:58:47.7	HIP 101808	22.05
2026-08-01 12:00	20:36:05.10	-25:00:11.2	HIP 101808	25.07
2026-08-02 00:00	20:35:49.15	-25:01:34.3	HIP 101808	28.30
2026-08-02 12:00	20:35:33.22	-25:02:56.9	HIP 101577	26.41
2026-08-03 00:00	20:35:17.30	-25:04:19.1	HIP 101577	24.58
2026-08-03 12:00	20:35:01.39	-25:05:40.7	HIP 101577	23.27
2026-08-04 00:00	20:34:45.50	-25:07:01.9	HIP 101577	22.55
2026-08-04 12:00	20:34:29.63	-25:08:22.5	HIP 101577	22.47
2026-08-05 00:00	20:34:13.78	-25:09:42.7	HIP 101384	22.61
2026-08-05 12:00	20:33:57.95	-25:11:02.3	HIP 101384	20.70
2026-08-06 00:00	20:33:42.14	-25:12:21.4	HIP 101384	19.36
2026-08-06 12:00	20:33:26.37	-25:13:39.9	HIP 101384	18.70
2026-08-07 00:00	20:33:10.62	-25:14:57.9	HIP 101384	18.80
2026-08-07 12:00	20:32:54.90	-25:16:15.4	HIP 101384	19.64
2026-08-08 00:00	20:32:39.22	-25:17:32.3	HIP 101384	21.12
2026-08-08 12:00	20:32:23.58	-25:18:48.6	HIP 101384	23.12
2026-08-09 00:00	20:32:07.97	-25:20:04.3	HIP 101384	25.51
2026-08-09 12:00	20:31:52.41	-25:21:19.5	HIP 101384	28.18
2026-08-10 00:00	20:31:36.89	-25:22:34.1	HIP 101360	30.89
2026-08-10 12:00	20:31:21.41	-25:23:48.0	HIP 101122	30.59
2026-08-11 00:00	20:31:05.99	-25:25:01.4	HIP 101122	27.46
2026-08-11 12:00	20:30:50.61	-25:26:14.2	HIP 101122	24.51
2026-08-12 00:00	20:30:35.29	-25:27:26.3	HIP 101122	21.80
2026-08-12 12:00	20:30:20.03	-25:28:37.8	HIP 101122	19.41
2026-08-13 00:00	20:30:04.82	-25:29:48.7	HIP 101122	17.47
2026-08-13 12:00	20:29:49.67	-25:30:58.9	HIP 101122	16.13
2026-08-14 00:00	20:29:34.59	-25:32:08.5	HIP 101122	15.55
2026-08-14 12:00	20:29:19.57	-25:33:17.5	HIP 101122	15.78
2026-08-15 00:00	20:29:04.62	-25:34:25.8	HIP 100947	14.42
2026-08-15 12:00	20:28:49.74	-25:35:33.4	HIP 100947	10.96
2026-08-16 00:00	20:28:34.93	-25:36:40.4	HIP 100947	7.59
2026-08-16 12:00	20:28:20.19	-25:37:46.7	HIP 100947	4.49
2026-08-17 00:00	20:28:05.53	-25:38:52.3	HIP 100947	2.66
2026-08-17 12:00	20:27:50.95	-25:39:57.2	HIP 100947	4.26
2026-08-18 00:00	20:27:36.45	-25:41:01.5	HIP 100947	7.26
2026-08-18 12:00	20:27:22.03	-25:42:05.1	HIP 100947	10.52
2026-08-19 00:00	20:27:07.69	-25:43:07.9	HIP 100947	13.83