メタデータ

項目	値
Designation	P/2011 N1 (ASH)
Type	P
Perihelion (tp_cal, UTC)	2012-05-31T06:52:34.999680Z
Orbit solution date (soln_date, UTC)	2021-04-15T23:31:52Z
Obs used	269
NEO	-
M1	12.800
K1	5.250
PC	-

オスキュレーティング軌道要素

項目	値
Epoch (epoch_cal, TDB)	2011-12-30.0000000
e	0.54594610
q (au)	2.857717
a (au)	6.293785
i (deg)	35.668884
Ω (om, deg)	77.690510
ω (w, deg)	331.056188
M (ma, deg)	350.431581

等級

散乱 + 全体線形

$$ M_a = (12.378 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

モデル定数

項目	値
H0	12.378
n	2.000
gf	0.999
gb	-0.500
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
2011-07-01	2012-02-01	+4.8034	-2.824
2012-09-29	2014-03-21	-1.2040	+2.406

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	21:11:24.08	-54:53:40.9	HIP 104497	14.49
2026-09-20 12:00	21:11:09.84	-54:52:18.1	HIP 104497	12.03
2026-09-21 00:00	21:10:55.94	-54:50:52.9	HIP 104497	9.58
2026-09-21 12:00	21:10:42.37	-54:49:25.2	HIP 104497	7.14
2026-09-22 00:00	21:10:29.14	-54:47:55.2	HIP 104497	4.72
2026-09-22 12:00	21:10:16.25	-54:46:22.8	HIP 104497	2.30
2026-09-23 00:00	21:10:03.71	-54:44:48.0	HIP 104497	0.11
2026-09-23 12:00	21:09:51.51	-54:43:11.0	HIP 104497	2.49
2026-09-24 00:00	21:09:39.66	-54:41:31.7	HIP 104497	4.87
2026-09-24 12:00	21:09:28.16	-54:39:50.0	HIP 104497	7.24
2026-09-25 00:00	21:09:17.01	-54:38:06.2	HIP 104497	9.60
2026-09-25 12:00	21:09:06.21	-54:36:20.1	HIP 104526	11.61
2026-09-26 00:00	21:08:55.76	-54:34:31.8	HIP 104322	12.91
2026-09-26 12:00	21:08:45.67	-54:32:41.4	HIP 104322	13.58
2026-09-27 00:00	21:08:35.93	-54:30:48.8	HIP 104322	14.66
2026-09-27 12:00	21:08:26.56	-54:28:54.1	HIP 104322	16.06
2026-09-28 00:00	21:08:17.54	-54:26:57.2	HIP 104308	14.49
2026-09-28 12:00	21:08:08.88	-54:24:58.3	HIP 104308	12.27
2026-09-29 00:00	21:08:00.58	-54:22:57.3	HIP 104308	10.07
2026-09-29 12:00	21:07:52.64	-54:20:54.3	HIP 104308	7.93
2026-09-30 00:00	21:07:45.07	-54:18:49.3	HIP 104308	5.91
2026-09-30 12:00	21:07:37.86	-54:16:42.2	HIP 104308	4.20
2026-10-01 00:00	21:07:31.01	-54:14:33.2	HIP 104308	3.34
2026-10-01 12:00	21:07:24.53	-54:12:22.2	HIP 104308	3.94
2026-10-02 00:00	21:07:18.42	-54:10:09.3	HIP 104308	5.56
2026-10-02 12:00	21:07:12.68	-54:07:54.5	HIP 104308	7.58
2026-10-03 00:00	21:07:07.30	-54:05:37.8	HIP 104308	9.76
2026-10-03 12:00	21:07:02.29	-54:03:19.2	HIP 104308	12.03
2026-10-04 00:00	21:06:57.65	-54:00:58.7	HIP 104308	14.34
2026-10-04 12:00	21:06:53.38	-53:58:36.4	HIP 104308	16.69
2026-10-05 00:00	21:06:49.48	-53:56:12.3	HIP 104308	19.06
2026-10-05 12:00	21:06:45.96	-53:53:46.4	HIP 104308	21.46
2026-10-06 00:00	21:06:42.80	-53:51:18.7	HIP 104308	23.88
2026-10-06 12:00	21:06:40.02	-53:48:49.3	HIP 104308	26.32
2026-10-07 00:00	21:06:37.61	-53:46:18.2	HIP 104308	28.79
2026-10-07 12:00	21:06:35.57	-53:43:45.3	HIP 104308	31.27
2026-10-08 00:00	21:06:33.90	-53:41:10.8	HIP 104359	30.43
2026-10-08 12:00	21:06:32.60	-53:38:34.6	HIP 104359	28.43
2026-10-09 00:00	21:06:31.68	-53:35:56.7	HIP 104359	26.49
2026-10-09 12:00	21:06:31.13	-53:33:17.2	HIP 104359	24.62
2026-10-10 00:00	21:06:30.95	-53:30:36.2	HIP 104359	22.84
2026-10-10 12:00	21:06:31.15	-53:27:53.5	HIP 104359	21.19
2026-10-11 00:00	21:06:31.71	-53:25:09.3	HIP 104359	19.72