メタデータ

項目	値
Designation	13P/Olbers
Type	P
Perihelion (tp_cal, UTC)	2024-06-30T17:24:30.931200Z
Orbit solution date (soln_date, UTC)	2026-07-28T14:18:43Z
Obs used	2605
NEO	Yes
M1	6.700
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)	2020-12-10.0000000
e	0.92970907
q (au)	1.173075
a (au)	16.688859
i (deg)	44.624173
Ω (om, deg)	85.872180
ω (w, deg)	64.511271
M (ma, deg)	341.224937

等級

散乱 + 全体線形

$$ M_a = (6.023 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

モデル定数

項目	値
H0	6.023
n	6.000
gf	0.998
gb	-0.963
k	1.000
δ90	9.995

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
2023-08-13	2024-06-30	+9.7493	-3.041
2024-06-30	2025-07-31	-0.2703	-1.962

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)
2026-09-20 00:00	18:32:39.18	-40:49:25.4	HIP 90856	7.45
2026-09-20 12:00	18:32:39.68	-40:48:46.5	HIP 90856	7.26
2026-09-21 00:00	18:32:40.35	-40:48:07.6	HIP 90856	7.15
2026-09-21 12:00	18:32:41.18	-40:47:28.5	HIP 90856	7.14
2026-09-22 00:00	18:32:42.18	-40:46:49.4	HIP 90856	7.21
2026-09-22 12:00	18:32:43.35	-40:46:10.2	HIP 90856	7.38
2026-09-23 00:00	18:32:44.67	-40:45:31.0	HIP 90856	7.65
2026-09-23 12:00	18:32:46.16	-40:44:51.7	HIP 90856	7.99
2026-09-24 00:00	18:32:47.82	-40:44:12.3	HIP 90856	8.41
2026-09-24 12:00	18:32:49.63	-40:43:32.8	HIP 90856	8.90
2026-09-25 00:00	18:32:51.61	-40:42:53.3	HIP 90856	9.46
2026-09-25 12:00	18:32:53.75	-40:42:13.8	HIP 90856	10.07
2026-09-26 00:00	18:32:56.04	-40:41:34.2	HIP 90856	10.73
2026-09-26 12:00	18:32:58.50	-40:40:54.5	HIP 90856	11.43
2026-09-27 00:00	18:33:01.12	-40:40:14.8	HIP 90856	12.17
2026-09-27 12:00	18:33:03.89	-40:39:35.1	HIP 90856	12.95
2026-09-28 00:00	18:33:06.82	-40:38:55.4	HIP 90856	13.76
2026-09-28 12:00	18:33:09.91	-40:38:15.6	HIP 90856	14.61
2026-09-29 00:00	18:33:13.15	-40:37:35.8	HIP 90856	15.48
2026-09-29 12:00	18:33:16.55	-40:36:56.0	HIP 90856	16.39
2026-09-30 00:00	18:33:20.11	-40:36:16.2	HIP 90856	17.32
2026-09-30 12:00	18:33:23.82	-40:35:36.4	HIP 90856	18.27
2026-10-01 00:00	18:33:27.68	-40:34:56.6	HIP 90856	19.25
2026-10-01 12:00	18:33:31.70	-40:34:16.7	HIP 90856	20.26
2026-10-02 00:00	18:33:35.87	-40:33:36.9	HIP 90856	21.29
2026-10-02 12:00	18:33:40.19	-40:32:57.1	HIP 90856	22.34
2026-10-03 00:00	18:33:44.67	-40:32:17.2	HIP 90856	23.42
2026-10-03 12:00	18:33:49.29	-40:31:37.4	HIP 90856	24.52
2026-10-04 00:00	18:33:54.07	-40:30:57.6	HIP 90856	25.65
2026-10-04 12:00	18:33:58.99	-40:30:17.8	HIP 90856	26.79
2026-10-05 00:00	18:34:04.06	-40:29:38.1	HIP 90856	27.96
2026-10-05 12:00	18:34:09.29	-40:28:58.3	HIP 90856	29.16
2026-10-06 00:00	18:34:14.66	-40:28:18.6	HIP 90856	30.37
2026-10-06 12:00	18:34:20.18	-40:27:38.9	HIP 90856	31.61
2026-10-07 00:00	18:34:25.84	-40:26:59.3	HIP 90856	32.87
2026-10-07 12:00	18:34:31.65	-40:26:19.7	HIP 90856	34.15
2026-10-08 00:00	18:34:37.61	-40:25:40.1	HIP 91330	35.09
2026-10-08 12:00	18:34:43.71	-40:25:00.6	HIP 91330	34.02
2026-10-09 00:00	18:34:49.95	-40:24:21.1	HIP 91330	32.94
2026-10-09 12:00	18:34:56.34	-40:23:41.7	HIP 91330	31.86
2026-10-10 00:00	18:35:02.87	-40:23:02.3	HIP 91330	30.77
2026-10-10 12:00	18:35:09.54	-40:22:23.0	HIP 91330	29.68
2026-10-11 00:00	18:35:16.35	-40:21:43.7	HIP 91330	28.59