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)
2026-05-12 00:00	00:15:42.75	+05:52:21.5	HIP 1249	2.01
2026-05-12 12:00	00:15:43.84	+05:52:29.8	HIP 1249	2.28
2026-05-13 00:00	00:15:44.92	+05:52:38.1	HIP 1249	2.55
2026-05-13 12:00	00:15:46.00	+05:52:46.3	HIP 1249	2.82
2026-05-14 00:00	00:15:47.06	+05:52:54.4	HIP 1249	3.10
2026-05-14 12:00	00:15:48.11	+05:53:02.6	HIP 1249	3.38
2026-05-15 00:00	00:15:49.16	+05:53:10.6	HIP 1249	3.66
2026-05-15 12:00	00:15:50.19	+05:53:18.6	HIP 1249	3.94
2026-05-16 00:00	00:15:51.21	+05:53:26.5	HIP 1249	4.21
2026-05-16 12:00	00:15:52.22	+05:53:34.4	HIP 1249	4.49
2026-05-17 00:00	00:15:53.22	+05:53:42.2	HIP 1249	4.76
2026-05-17 12:00	00:15:54.22	+05:53:50.0	HIP 1249	5.03
2026-05-18 00:00	00:15:55.20	+05:53:57.7	HIP 1249	5.30
2026-05-18 12:00	00:15:56.17	+05:54:05.4	HIP 1249	5.57
2026-05-19 00:00	00:15:57.12	+05:54:13.0	HIP 1249	5.84
2026-05-19 12:00	00:15:58.07	+05:54:20.5	HIP 1249	6.10
2026-05-20 00:00	00:15:59.01	+05:54:27.9	HIP 1249	6.36
2026-05-20 12:00	00:15:59.94	+05:54:35.4	HIP 1249	6.62
2026-05-21 00:00	00:16:00.85	+05:54:42.7	HIP 1249	6.88
2026-05-21 12:00	00:16:01.76	+05:54:50.0	HIP 1249	7.13
2026-05-22 00:00	00:16:02.65	+05:54:57.2	HIP 1249	7.38
2026-05-22 12:00	00:16:03.53	+05:55:04.4	HIP 1249	7.63
2026-05-23 00:00	00:16:04.40	+05:55:11.5	HIP 1249	7.87
2026-05-23 12:00	00:16:05.26	+05:55:18.5	HIP 1249	8.11
2026-05-24 00:00	00:16:06.11	+05:55:25.4	HIP 1249	8.35
2026-05-24 12:00	00:16:06.94	+05:55:32.3	HIP 1249	8.59
2026-05-25 00:00	00:16:07.77	+05:55:39.2	HIP 1249	8.82
2026-05-25 12:00	00:16:08.58	+05:55:45.9	HIP 1249	9.05
2026-05-26 00:00	00:16:09.38	+05:55:52.6	HIP 1249	9.28
2026-05-26 12:00	00:16:10.17	+05:55:59.3	HIP 1249	9.50
2026-05-27 00:00	00:16:10.95	+05:56:05.8	HIP 1249	9.73
2026-05-27 12:00	00:16:11.71	+05:56:12.3	HIP 1249	9.94
2026-05-28 00:00	00:16:12.47	+05:56:18.8	HIP 1249	10.16
2026-05-28 12:00	00:16:13.21	+05:56:25.1	HIP 1249	10.37
2026-05-29 00:00	00:16:13.94	+05:56:31.4	HIP 1249	10.58
2026-05-29 12:00	00:16:14.66	+05:56:37.7	HIP 1249	10.79
2026-05-30 00:00	00:16:15.37	+05:56:43.8	HIP 1249	10.99
2026-05-30 12:00	00:16:16.06	+05:56:49.9	HIP 1249	11.19
2026-05-31 00:00	00:16:16.75	+05:56:55.9	HIP 1249	11.39
2026-05-31 12:00	00:16:17.42	+05:57:01.9	HIP 1249	11.58
2026-06-01 00:00	00:16:18.07	+05:57:07.7	HIP 1249	11.77
2026-06-01 12:00	00:16:18.72	+05:57:13.5	HIP 1249	11.96
2026-06-02 00:00	00:16:19.35	+05:57:19.3	HIP 1249	12.14