メタデータ

項目	値
Designation	C/1969 Y1 (Bennett)
Type	C
Perihelion (tp_cal, UTC)	1970-03-20T01:05:24.547200Z
Orbit solution date (soln_date, UTC)	2021-04-15T23:29:19Z
Obs used	529
NEO	-
M1	4.600
K1	12.000
PC	-

オスキュレーティング軌道要素

項目	値
Epoch (epoch_cal, TDB)	1970-04-12.0000000
e	0.99629328
q (au)	0.537620
a (au)	145.039330
i (deg)	90.039811
Ω (om, deg)	224.657683
ω (w, deg)	354.149089
M (ma, deg)	0.012952

等級

散乱 + 全体線形

$$ M_a = (4.085 + 3.365\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

モデル定数

項目	値
H0	4.085
n	3.365
gf	0.800
gb	-0.500
k	1.000
δ90	1.000

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
1969-12-28	1970-03-20	+3.0975	+0.766
1970-03-20	1970-04-13	-4.8648	-1.069
1970-04-13	1970-05-01	+0.0535	-0.380
1970-05-01	1970-11-20	+1.8732	-0.612

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	02:30:49.43	+29:27:56.9	HIP 11823	24.32
2026-05-12 12:00	02:30:51.05	+29:28:04.4	HIP 11823	24.04
2026-05-13 00:00	02:30:52.67	+29:28:11.9	HIP 11823	23.77
2026-05-13 12:00	02:30:54.28	+29:28:19.5	HIP 11823	23.50
2026-05-14 00:00	02:30:55.89	+29:28:27.1	HIP 11823	23.23
2026-05-14 12:00	02:30:57.50	+29:28:34.7	HIP 11823	22.97
2026-05-15 00:00	02:30:59.11	+29:28:42.4	HIP 11823	22.71
2026-05-15 12:00	02:31:00.71	+29:28:50.0	HIP 11823	22.45
2026-05-16 00:00	02:31:02.31	+29:28:57.8	HIP 11823	22.20
2026-05-16 12:00	02:31:03.90	+29:29:05.5	HIP 11823	21.95
2026-05-17 00:00	02:31:05.49	+29:29:13.3	HIP 11823	21.71
2026-05-17 12:00	02:31:07.08	+29:29:21.1	HIP 11823	21.47
2026-05-18 00:00	02:31:08.66	+29:29:29.0	HIP 11823	21.24
2026-05-18 12:00	02:31:10.24	+29:29:36.8	HIP 11823	21.01
2026-05-19 00:00	02:31:11.82	+29:29:44.7	HIP 11823	20.79
2026-05-19 12:00	02:31:13.39	+29:29:52.7	HIP 11823	20.57
2026-05-20 00:00	02:31:14.96	+29:30:00.6	HIP 11823	20.36
2026-05-20 12:00	02:31:16.52	+29:30:08.6	HIP 11823	20.15
2026-05-21 00:00	02:31:18.08	+29:30:16.6	HIP 11823	19.95
2026-05-21 12:00	02:31:19.64	+29:30:24.6	HIP 11823	19.76
2026-05-22 00:00	02:31:21.19	+29:30:32.7	HIP 11823	19.57
2026-05-22 12:00	02:31:22.73	+29:30:40.8	HIP 11823	19.38
2026-05-23 00:00	02:31:24.27	+29:30:48.9	HIP 11823	19.21
2026-05-23 12:00	02:31:25.80	+29:30:57.0	HIP 11823	19.03
2026-05-24 00:00	02:31:27.33	+29:31:05.2	HIP 11823	18.87
2026-05-24 12:00	02:31:28.86	+29:31:13.3	HIP 11823	18.71
2026-05-25 00:00	02:31:30.38	+29:31:21.5	HIP 11823	18.56
2026-05-25 12:00	02:31:31.89	+29:31:29.7	HIP 11823	18.41
2026-05-26 00:00	02:31:33.40	+29:31:38.0	HIP 11823	18.28
2026-05-26 12:00	02:31:34.90	+29:31:46.2	HIP 11823	18.15
2026-05-27 00:00	02:31:36.40	+29:31:54.5	HIP 11823	18.02
2026-05-27 12:00	02:31:37.89	+29:32:02.8	HIP 11823	17.91
2026-05-28 00:00	02:31:39.38	+29:32:11.1	HIP 11823	17.80
2026-05-28 12:00	02:31:40.86	+29:32:19.4	HIP 11823	17.69
2026-05-29 00:00	02:31:42.33	+29:32:27.7	HIP 11823	17.60
2026-05-29 12:00	02:31:43.80	+29:32:36.1	HIP 11823	17.51
2026-05-30 00:00	02:31:45.26	+29:32:44.4	HIP 11823	17.43
2026-05-30 12:00	02:31:46.71	+29:32:52.8	HIP 11823	17.36
2026-05-31 00:00	02:31:48.16	+29:33:01.2	HIP 11823	17.30
2026-05-31 12:00	02:31:49.60	+29:33:09.6	HIP 11823	17.24
2026-06-01 00:00	02:31:51.04	+29:33:18.1	HIP 11823	17.19
2026-06-01 12:00	02:31:52.46	+29:33:26.5	HIP 11823	17.15
2026-06-02 00:00	02:31:53.89	+29:33:34.9	HIP 11823	17.12