メタデータ

項目	値
Designation	C/1984 N1 (Austin)
Type	C
Perihelion (tp_cal, UTC)	1984-08-12T03:17:25.103040Z
Orbit solution date (soln_date, UTC)	2021-04-15T23:29:31Z
Obs used	100
NEO	-
M1	10.800
K1	15.750
PC	-

オスキュレーティング軌道要素

項目	値
Epoch (epoch_cal, TDB)	1984-09-13.0000000
e	0.99984838
q (au)	0.291283
a (au)	1921.159758
i (deg)	164.153161
Ω (om, deg)	171.577849
ω (w, deg)	353.128957
M (ma, deg)	0.000373

等級

散乱 + 全体線形

$$ M_a = (7.754 + 2.989\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

モデル定数

項目	値
H0	7.754
n	2.989
gf	0.800
gb	-0.500
k	0.800
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
1984-07-08	1984-07-30	+8.4930	+3.074
1984-07-30	1984-08-07	-0.7853	+0.326
1984-08-25	1984-09-14	-0.7139	-0.544
1984-09-14	1984-11-28	+5.1315	-0.517

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)
2026-03-26 00:00	00:13:28.81	+05:36:58.7	HIP 1050	5.98
2026-03-26 12:00	00:13:30.41	+05:37:09.0	HIP 1050	6.36
2026-03-27 00:00	00:13:32.01	+05:37:19.3	HIP 1050	6.74
2026-03-27 12:00	00:13:33.62	+05:37:29.6	HIP 1050	7.12
2026-03-28 00:00	00:13:35.22	+05:37:39.9	HIP 1050	7.51
2026-03-28 12:00	00:13:36.82	+05:37:50.2	HIP 1050	7.91
2026-03-29 00:00	00:13:38.42	+05:38:00.5	HIP 1050	8.31
2026-03-29 12:00	00:13:40.02	+05:38:10.8	HIP 1050	8.71
2026-03-30 00:00	00:13:41.61	+05:38:21.2	HIP 1050	9.11
2026-03-30 12:00	00:13:43.21	+05:38:31.5	HIP 1050	9.52
2026-03-31 00:00	00:13:44.81	+05:38:41.9	HIP 1050	9.93
2026-03-31 12:00	00:13:46.40	+05:38:52.2	HIP 1050	10.34
2026-04-01 00:00	00:13:47.99	+05:39:02.6	HIP 1050	10.75
2026-04-01 12:00	00:13:49.58	+05:39:13.0	HIP 1050	11.16
2026-04-02 00:00	00:13:51.17	+05:39:23.3	HIP 1050	11.58
2026-04-02 12:00	00:13:52.75	+05:39:33.7	HIP 1050	11.99
2026-04-03 00:00	00:13:54.34	+05:39:44.1	HIP 1050	12.40
2026-04-03 12:00	00:13:55.92	+05:39:54.5	HIP 1050	12.82
2026-04-04 00:00	00:13:57.50	+05:40:04.8	HIP 1050	13.24
2026-04-04 12:00	00:13:59.07	+05:40:15.2	HIP 1050	13.65
2026-04-05 00:00	00:14:00.65	+05:40:25.6	HIP 1050	14.07
2026-04-05 12:00	00:14:02.22	+05:40:36.0	HIP 1050	14.48
2026-04-06 00:00	00:14:03.79	+05:40:46.4	HIP 1050	14.90
2026-04-06 12:00	00:14:05.36	+05:40:56.7	HIP 1199	14.73
2026-04-07 00:00	00:14:06.92	+05:41:07.1	HIP 1199	14.44
2026-04-07 12:00	00:14:08.48	+05:41:17.5	HIP 1199	14.16
2026-04-08 00:00	00:14:10.04	+05:41:27.8	HIP 1199	13.88
2026-04-08 12:00	00:14:11.59	+05:41:38.2	HIP 1199	13.62
2026-04-09 00:00	00:14:13.14	+05:41:48.5	HIP 1199	13.36
2026-04-09 12:00	00:14:14.69	+05:41:58.9	HIP 1199	13.11
2026-04-10 00:00	00:14:16.23	+05:42:09.2	HIP 1199	12.87
2026-04-10 12:00	00:14:17.77	+05:42:19.6	HIP 1199	12.64
2026-04-11 00:00	00:14:19.31	+05:42:29.9	HIP 1199	12.43
2026-04-11 12:00	00:14:20.84	+05:42:40.2	HIP 1199	12.22
2026-04-12 00:00	00:14:22.37	+05:42:50.5	HIP 1199	12.03
2026-04-12 12:00	00:14:23.89	+05:43:00.8	HIP 1199	11.85
2026-04-13 00:00	00:14:25.41	+05:43:11.1	HIP 1199	11.68
2026-04-13 12:00	00:14:26.93	+05:43:21.3	HIP 1199	11.52
2026-04-14 00:00	00:14:28.44	+05:43:31.6	HIP 1199	11.38
2026-04-14 12:00	00:14:29.94	+05:43:41.8	HIP 1199	11.25
2026-04-15 00:00	00:14:31.44	+05:43:52.0	HIP 1199	11.13
2026-04-15 12:00	00:14:32.94	+05:44:02.2	HIP 1199	11.03
2026-04-16 00:00	00:14:34.43	+05:44:12.4	HIP 1199	10.95