メタデータ

項目	値
Designation	152P/Helin-Lawrence
Type	P
Perihelion (tp_cal, UTC)	2012-07-08T08:45:15.160320Z
Orbit solution date (soln_date, UTC)	2025-03-06T13:42:28Z
Obs used	1298
NEO	-
M1	12.700
K1	6.000
PC	-

オスキュレーティング軌道要素

項目	値
Epoch (epoch_cal, TDB)	2015-02-09.0000000
e	0.30721897
q (au)	3.112792
a (au)	4.493183
i (deg)	9.868309
Ω (om, deg)	91.899208
ω (w, deg)	163.585758
M (ma, deg)	97.858042

等級

散乱 + 全体線形

$$ M_a = (12.595 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

モデル定数

項目	値
H0	12.595
n	2.000
gf	1.000
gb	-0.873
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

残差 (区間線形)

$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$

開始日 (UTC)	終了日 (UTC)	a	b
2020-02-20	2022-01-12	+17.5656	-9.164
2022-01-12	2023-08-23	-11.7992	+7.162
2023-08-23	2025-01-04	+22.4248	-14.516

log10 r = log10(太陽距離/AU)、Δ = 地球距離(AU)

ファインディングチャート

天体暦

Date/Time (UTC)	RA (J2000)	Dec (J2000)	Nearest HIP	Dist from HIP (arcmin)
2026-09-20 00:00	05:38:21.53	+20:24:54.1	HIP 26387	18.31
2026-09-20 12:00	05:38:27.73	+20:25:00.1	HIP 26387	19.75
2026-09-21 00:00	05:38:33.75	+20:25:06.0	HIP 26387	21.16
2026-09-21 12:00	05:38:39.61	+20:25:11.8	HIP 26387	22.53
2026-09-22 00:00	05:38:45.29	+20:25:17.6	HIP 26539	23.24
2026-09-22 12:00	05:38:50.81	+20:25:23.2	HIP 26539	23.45
2026-09-23 00:00	05:38:56.15	+20:25:28.8	HIP 26568	23.64
2026-09-23 12:00	05:39:01.32	+20:25:34.3	HIP 26568	23.77
2026-09-24 00:00	05:39:06.32	+20:25:39.7	HIP 26568	23.95
2026-09-24 12:00	05:39:11.15	+20:25:45.0	HIP 26568	24.18
2026-09-25 00:00	05:39:15.80	+20:25:50.3	HIP 26568	24.46
2026-09-25 12:00	05:39:20.28	+20:25:55.5	HIP 26568	24.77
2026-09-26 00:00	05:39:24.58	+20:26:00.6	HIP 26568	25.10
2026-09-26 12:00	05:39:28.71	+20:26:05.7	HIP 26568	25.46
2026-09-27 00:00	05:39:32.66	+20:26:10.6	HIP 26568	25.83
2026-09-27 12:00	05:39:36.43	+20:26:15.6	HIP 26568	26.22
2026-09-28 00:00	05:39:40.03	+20:26:20.4	HIP 26568	26.61
2026-09-28 12:00	05:39:43.45	+20:26:25.2	HIP 26568	27.01
2026-09-29 00:00	05:39:46.69	+20:26:29.9	HIP 26568	27.40
2026-09-29 12:00	05:39:49.75	+20:26:34.6	HIP 26568	27.79
2026-09-30 00:00	05:39:52.63	+20:26:39.2	HIP 26568	28.18
2026-09-30 12:00	05:39:55.34	+20:26:43.7	HIP 26568	28.55
2026-10-01 00:00	05:39:57.85	+20:26:48.2	HIP 26770	28.83
2026-10-01 12:00	05:40:00.19	+20:26:52.7	HIP 26770	28.57
2026-10-02 00:00	05:40:02.35	+20:26:57.0	HIP 26770	28.33
2026-10-02 12:00	05:40:04.32	+20:27:01.4	HIP 26770	28.13
2026-10-03 00:00	05:40:06.11	+20:27:05.7	HIP 26770	27.95
2026-10-03 12:00	05:40:07.71	+20:27:09.9	HIP 26770	27.81
2026-10-04 00:00	05:40:09.13	+20:27:14.1	HIP 26770	27.69
2026-10-04 12:00	05:40:10.37	+20:27:18.2	HIP 26770	27.60
2026-10-05 00:00	05:40:11.42	+20:27:22.3	HIP 26770	27.53
2026-10-05 12:00	05:40:12.28	+20:27:26.3	HIP 26770	27.48
2026-10-06 00:00	05:40:12.95	+20:27:30.4	HIP 26770	27.46
2026-10-06 12:00	05:40:13.44	+20:27:34.3	HIP 26770	27.46
2026-10-07 00:00	05:40:13.74	+20:27:38.2	HIP 26770	27.48
2026-10-07 12:00	05:40:13.85	+20:27:42.1	HIP 26770	27.53
2026-10-08 00:00	05:40:13.77	+20:27:46.0	HIP 26770	27.59
2026-10-08 12:00	05:40:13.51	+20:27:49.8	HIP 26770	27.68
2026-10-09 00:00	05:40:13.05	+20:27:53.6	HIP 26770	27.78
2026-10-09 12:00	05:40:12.41	+20:27:57.4	HIP 26770	27.91
2026-10-10 00:00	05:40:11.57	+20:28:01.1	HIP 26770	28.07
2026-10-10 12:00	05:40:10.55	+20:28:04.8	HIP 26770	28.24
2026-10-11 00:00	05:40:09.33	+20:28:08.5	HIP 26770	28.44