メタデータ
| 項目 |
値 |
| Designation |
C/1968 Y1 (Thomas) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1969-01-12T06:16:18.609600Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:19Z |
| Obs used |
43 |
| NEO |
- |
| M1 |
5.800 |
| K1 |
10.500 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
1969-02-14.0000000 |
| e |
0.99530224 |
| q (au) |
3.316098 |
| a (au) |
705.888695 |
| i (deg) |
45.229346 |
| Ω (om, deg) |
16.110035 |
| ω (w, deg) |
82.582846 |
| M (ma, deg) |
0.001721 |
等級
散乱 + 全体線形
$$
M_a = (6.454 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
6.454 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.800 |
| 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
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
15:27:42.90 |
-58:19:37.8 |
HIP 75842 |
14.51 |
| 2026-07-29 12:00 |
15:27:42.13 |
-58:19:23.7 |
HIP 75842 |
14.63 |
| 2026-07-30 00:00 |
15:27:41.37 |
-58:19:09.6 |
HIP 75842 |
14.76 |
| 2026-07-30 12:00 |
15:27:40.64 |
-58:18:55.4 |
HIP 75842 |
14.89 |
| 2026-07-31 00:00 |
15:27:39.93 |
-58:18:41.3 |
HIP 75842 |
15.02 |
| 2026-07-31 12:00 |
15:27:39.24 |
-58:18:27.2 |
HIP 75842 |
15.15 |
| 2026-08-01 00:00 |
15:27:38.58 |
-58:18:13.0 |
HIP 75842 |
15.28 |
| 2026-08-01 12:00 |
15:27:37.93 |
-58:17:58.9 |
HIP 75842 |
15.41 |
| 2026-08-02 00:00 |
15:27:37.31 |
-58:17:44.8 |
HIP 75842 |
15.54 |
| 2026-08-02 12:00 |
15:27:36.71 |
-58:17:30.7 |
HIP 75842 |
15.67 |
| 2026-08-03 00:00 |
15:27:36.14 |
-58:17:16.6 |
HIP 75842 |
15.80 |
| 2026-08-03 12:00 |
15:27:35.58 |
-58:17:02.5 |
HIP 75842 |
15.92 |
| 2026-08-04 00:00 |
15:27:35.05 |
-58:16:48.4 |
HIP 75842 |
16.05 |
| 2026-08-04 12:00 |
15:27:34.54 |
-58:16:34.3 |
HIP 75842 |
16.18 |
| 2026-08-05 00:00 |
15:27:34.06 |
-58:16:20.2 |
HIP 75842 |
16.31 |
| 2026-08-05 12:00 |
15:27:33.59 |
-58:16:06.1 |
HIP 75842 |
16.44 |
| 2026-08-06 00:00 |
15:27:33.15 |
-58:15:52.1 |
HIP 75842 |
16.57 |
| 2026-08-06 12:00 |
15:27:32.73 |
-58:15:38.1 |
HIP 75842 |
16.70 |
| 2026-08-07 00:00 |
15:27:32.34 |
-58:15:24.0 |
HIP 75842 |
16.82 |
| 2026-08-07 12:00 |
15:27:31.97 |
-58:15:10.0 |
HIP 75842 |
16.95 |
| 2026-08-08 00:00 |
15:27:31.62 |
-58:14:56.1 |
HIP 75842 |
17.08 |
| 2026-08-08 12:00 |
15:27:31.29 |
-58:14:42.1 |
HIP 75842 |
17.20 |
| 2026-08-09 00:00 |
15:27:30.99 |
-58:14:28.1 |
HIP 75842 |
17.33 |
| 2026-08-09 12:00 |
15:27:30.70 |
-58:14:14.2 |
HIP 75842 |
17.45 |
| 2026-08-10 00:00 |
15:27:30.45 |
-58:14:00.3 |
HIP 75842 |
17.58 |
| 2026-08-10 12:00 |
15:27:30.21 |
-58:13:46.4 |
HIP 75842 |
17.70 |
| 2026-08-11 00:00 |
15:27:30.00 |
-58:13:32.6 |
HIP 75842 |
17.82 |
| 2026-08-11 12:00 |
15:27:29.81 |
-58:13:18.7 |
HIP 75842 |
17.94 |
| 2026-08-12 00:00 |
15:27:29.64 |
-58:13:04.9 |
HIP 75842 |
18.07 |
| 2026-08-12 12:00 |
15:27:29.50 |
-58:12:51.2 |
HIP 75842 |
18.19 |
| 2026-08-13 00:00 |
15:27:29.38 |
-58:12:37.4 |
HIP 75842 |
18.31 |
| 2026-08-13 12:00 |
15:27:29.29 |
-58:12:23.7 |
HIP 75842 |
18.42 |
| 2026-08-14 00:00 |
15:27:29.21 |
-58:12:10.0 |
HIP 75842 |
18.54 |
| 2026-08-14 12:00 |
15:27:29.16 |
-58:11:56.3 |
HIP 75842 |
18.66 |
| 2026-08-15 00:00 |
15:27:29.14 |
-58:11:42.7 |
HIP 75842 |
18.78 |
| 2026-08-15 12:00 |
15:27:29.13 |
-58:11:29.1 |
HIP 75842 |
18.89 |
| 2026-08-16 00:00 |
15:27:29.15 |
-58:11:15.5 |
HIP 75842 |
19.01 |
| 2026-08-16 12:00 |
15:27:29.19 |
-58:11:02.0 |
HIP 75842 |
19.12 |
| 2026-08-17 00:00 |
15:27:29.26 |
-58:10:48.5 |
HIP 75842 |
19.23 |
| 2026-08-17 12:00 |
15:27:29.35 |
-58:10:35.1 |
HIP 75842 |
19.34 |
| 2026-08-18 00:00 |
15:27:29.46 |
-58:10:21.7 |
HIP 75842 |
19.45 |
| 2026-08-18 12:00 |
15:27:29.59 |
-58:10:08.3 |
HIP 75842 |
19.56 |
| 2026-08-19 00:00 |
15:27:29.75 |
-58:09:55.0 |
HIP 75842 |
19.67 |