メタデータ
| 項目 |
値 |
| Designation |
C/2017 O1 (ASASSN) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2017-10-14T18:50:39.171840Z |
| Orbit solution date (soln_date, UTC) |
2022-07-31T01:42:28Z |
| Obs used |
2877 |
| NEO |
- |
| M1 |
12.400 |
| K1 |
8.750 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2017-10-13.0000000 |
| e |
0.99642549 |
| q (au) |
1.498687 |
| a (au) |
419.270415 |
| i (deg) |
39.848413 |
| Ω (om, deg) |
25.809488 |
| ω (w, deg) |
20.907853 |
| M (ma, deg) |
359.999795 |
等級
散乱 + 全体線形
$$
M_a = (12.630 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
12.630 |
| n |
2.000 |
| gf |
1.000 |
| 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 |
| 2017-07-20 |
2017-10-14 |
-12.1999 |
+1.263 |
| 2017-10-14 |
2019-03-12 |
+7.6667 |
-2.172 |
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) |
| 2026-06-01 00:00 |
13:10:53.12 |
-01:12:59.2 |
HIP 64351 |
21.30 |
| 2026-06-01 12:00 |
13:10:50.20 |
-01:12:52.8 |
HIP 64351 |
21.69 |
| 2026-06-02 00:00 |
13:10:47.31 |
-01:12:46.7 |
HIP 64351 |
22.10 |
| 2026-06-02 12:00 |
13:10:44.46 |
-01:12:40.8 |
HIP 64351 |
22.51 |
| 2026-06-03 00:00 |
13:10:41.64 |
-01:12:35.1 |
HIP 64351 |
22.92 |
| 2026-06-03 12:00 |
13:10:38.86 |
-01:12:29.7 |
HIP 64351 |
23.35 |
| 2026-06-04 00:00 |
13:10:36.12 |
-01:12:24.6 |
HIP 64351 |
23.78 |
| 2026-06-04 12:00 |
13:10:33.41 |
-01:12:19.7 |
HIP 64351 |
24.21 |
| 2026-06-05 00:00 |
13:10:30.74 |
-01:12:15.0 |
HIP 64351 |
24.64 |
| 2026-06-05 12:00 |
13:10:28.10 |
-01:12:10.7 |
HIP 64351 |
25.08 |
| 2026-06-06 00:00 |
13:10:25.51 |
-01:12:06.6 |
HIP 64351 |
25.52 |
| 2026-06-06 12:00 |
13:10:22.95 |
-01:12:02.7 |
HIP 64351 |
25.96 |
| 2026-06-07 00:00 |
13:10:20.43 |
-01:11:59.1 |
HIP 64351 |
26.39 |
| 2026-06-07 12:00 |
13:10:17.94 |
-01:11:55.8 |
HIP 64351 |
26.83 |
| 2026-06-08 00:00 |
13:10:15.49 |
-01:11:52.7 |
HIP 64351 |
27.26 |
| 2026-06-08 12:00 |
13:10:13.08 |
-01:11:49.9 |
HIP 64351 |
27.69 |
| 2026-06-09 00:00 |
13:10:10.71 |
-01:11:47.3 |
HIP 64351 |
28.12 |
| 2026-06-09 12:00 |
13:10:08.38 |
-01:11:45.0 |
HIP 64351 |
28.54 |
| 2026-06-10 00:00 |
13:10:06.08 |
-01:11:43.0 |
HIP 64351 |
28.96 |
| 2026-06-10 12:00 |
13:10:03.83 |
-01:11:41.2 |
HIP 64351 |
29.37 |
| 2026-06-11 00:00 |
13:10:01.61 |
-01:11:39.7 |
HIP 64351 |
29.78 |
| 2026-06-11 12:00 |
13:09:59.43 |
-01:11:38.5 |
HIP 64351 |
30.19 |
| 2026-06-12 00:00 |
13:09:57.29 |
-01:11:37.5 |
HIP 64351 |
30.59 |
| 2026-06-12 12:00 |
13:09:55.19 |
-01:11:36.8 |
HIP 64351 |
30.98 |
| 2026-06-13 00:00 |
13:09:53.13 |
-01:11:36.3 |
HIP 64351 |
31.36 |
| 2026-06-13 12:00 |
13:09:51.10 |
-01:11:36.1 |
HIP 64351 |
31.74 |
| 2026-06-14 00:00 |
13:09:49.12 |
-01:11:36.2 |
HIP 64351 |
32.12 |
| 2026-06-14 12:00 |
13:09:47.18 |
-01:11:36.5 |
HIP 64351 |
32.48 |
| 2026-06-15 00:00 |
13:09:45.27 |
-01:11:37.1 |
HIP 64351 |
32.84 |
| 2026-06-15 12:00 |
13:09:43.41 |
-01:11:38.0 |
HIP 64351 |
33.19 |
| 2026-06-16 00:00 |
13:09:41.59 |
-01:11:39.1 |
HIP 64351 |
33.53 |
| 2026-06-16 12:00 |
13:09:39.80 |
-01:11:40.5 |
HIP 64351 |
33.87 |
| 2026-06-17 00:00 |
13:09:38.06 |
-01:11:42.2 |
HIP 64351 |
34.19 |
| 2026-06-17 12:00 |
13:09:36.36 |
-01:11:44.1 |
HIP 64351 |
34.51 |
| 2026-06-18 00:00 |
13:09:34.69 |
-01:11:46.3 |
HIP 64351 |
34.82 |
| 2026-06-18 12:00 |
13:09:33.07 |
-01:11:48.8 |
HIP 64351 |
35.12 |
| 2026-06-19 00:00 |
13:09:31.49 |
-01:11:51.5 |
HIP 64351 |
35.42 |
| 2026-06-19 12:00 |
13:09:29.95 |
-01:11:54.4 |
HIP 64351 |
35.70 |
| 2026-06-20 00:00 |
13:09:28.45 |
-01:11:57.7 |
HIP 64351 |
35.98 |
| 2026-06-20 12:00 |
13:09:26.99 |
-01:12:01.2 |
HIP 64247 |
36.22 |
| 2026-06-21 00:00 |
13:09:25.57 |
-01:12:05.0 |
HIP 64247 |
36.38 |
| 2026-06-21 12:00 |
13:09:24.19 |
-01:12:09.0 |
HIP 64247 |
36.53 |
| 2026-06-22 00:00 |
13:09:22.85 |
-01:12:13.3 |
HIP 64247 |
36.70 |