メタデータ

項目	値
Designation	473P/NEAT
Type	P
Perihelion (tp_cal, UTC)	2001-11-04T17:20:30.220800Z
Orbit solution date (soln_date, UTC)	2024-06-30T00:42:21Z
Obs used	520
NEO	-
M1	11.200
K1	25.750
PC	0.030

オスキュレーティング軌道要素

項目	値
Epoch (epoch_cal, TDB)	2008-08-01.0000000
e	0.82249544
q (au)	1.407115
a (au)	7.927206
i (deg)	56.948538
Ω (om, deg)	22.184978
ω (w, deg)	43.106501
M (ma, deg)	108.688703

等級

散乱 + 全体線形

$$ M_a = (14.080 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

モデル定数

項目	値
H0	14.080
n	6.000
gf	1.000
gb	-1.000
k	0.800
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
2023-11-29	2024-05-08	+16.9214	-4.614
2024-05-08	2024-06-25	-14.5858	+3.980

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)
2026-05-12 00:00	13:08:16.55	-10:56:35.6	HIP 64078	13.39
2026-05-12 12:00	13:08:02.66	-10:56:00.4	HIP 64078	11.79
2026-05-13 00:00	13:07:48.88	-10:55:25.5	HIP 64078	11.07
2026-05-13 12:00	13:07:35.22	-10:54:51.1	HIP 64078	11.38
2026-05-14 00:00	13:07:21.68	-10:54:17.1	HIP 64078	12.63
2026-05-14 12:00	13:07:08.25	-10:53:43.6	HIP 64078	14.55
2026-05-15 00:00	13:06:54.94	-10:53:10.4	HIP 64078	16.90
2026-05-15 12:00	13:06:41.75	-10:52:37.8	HIP 64078	19.50
2026-05-16 00:00	13:06:28.69	-10:52:05.5	HIP 64078	22.26
2026-05-16 12:00	13:06:15.74	-10:51:33.8	HIP 63896	23.02
2026-05-17 00:00	13:06:02.92	-10:51:02.5	HIP 63896	21.57
2026-05-17 12:00	13:05:50.23	-10:50:31.7	HIP 63896	20.52
2026-05-18 00:00	13:05:37.66	-10:50:01.3	HIP 63896	19.94
2026-05-18 12:00	13:05:25.21	-10:49:31.5	HIP 63896	19.83
2026-05-19 00:00	13:05:12.89	-10:49:02.1	HIP 63896	20.21
2026-05-19 12:00	13:05:00.70	-10:48:33.3	HIP 63896	21.02
2026-05-20 00:00	13:04:48.64	-10:48:05.0	HIP 63896	22.21
2026-05-20 12:00	13:04:36.71	-10:47:37.2	HIP 63896	23.70
2026-05-21 00:00	13:04:24.91	-10:47:09.9	HIP 63896	25.44
2026-05-21 12:00	13:04:13.24	-10:46:43.2	HIP 63896	27.36
2026-05-22 00:00	13:04:01.70	-10:46:17.0	HIP 63896	29.42
2026-05-22 12:00	13:03:50.29	-10:45:51.3	HIP 63896	31.58
2026-05-23 00:00	13:03:39.01	-10:45:26.2	HIP 63896	33.82
2026-05-23 12:00	13:03:27.87	-10:45:01.6	HIP 63896	36.11
2026-05-24 00:00	13:03:16.86	-10:44:37.6	HIP 63555	37.21
2026-05-24 12:00	13:03:05.99	-10:44:14.2	HIP 63520	35.01
2026-05-25 00:00	13:02:55.25	-10:43:51.3	HIP 63520	32.85
2026-05-25 12:00	13:02:44.65	-10:43:29.0	HIP 63520	30.80
2026-05-26 00:00	13:02:34.18	-10:43:07.2	HIP 63520	28.86
2026-05-26 12:00	13:02:23.85	-10:42:46.1	HIP 63520	27.06
2026-05-27 00:00	13:02:13.65	-10:42:25.5	HIP 63520	25.40
2026-05-27 12:00	13:02:03.59	-10:42:05.5	HIP 63520	23.91
2026-05-28 00:00	13:01:53.67	-10:41:46.1	HIP 63520	22.60
2026-05-28 12:00	13:01:43.88	-10:41:27.3	HIP 63520	21.51
2026-05-29 00:00	13:01:34.23	-10:41:09.1	HIP 63520	20.66
2026-05-29 12:00	13:01:24.72	-10:40:51.5	HIP 63520	20.05
2026-05-30 00:00	13:01:15.35	-10:40:34.6	HIP 63520	19.71
2026-05-30 12:00	13:01:06.12	-10:40:18.2	HIP 63520	19.63
2026-05-31 00:00	13:00:57.02	-10:40:02.4	HIP 63520	19.80
2026-05-31 12:00	13:00:48.07	-10:39:47.3	HIP 63520	20.21
2026-06-01 00:00	13:00:39.25	-10:39:32.8	HIP 63520	20.82
2026-06-01 12:00	13:00:30.57	-10:39:18.9	HIP 63520	21.62
2026-06-02 00:00	13:00:22.03	-10:39:05.6	HIP 63520	22.58