メタデータ
| 項目 |
値 |
| Designation |
C/2015 K7 (COIAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2013-02-19T19:51:17.665920Z |
| Orbit solution date (soln_date, UTC) |
2024-12-23T14:42:02Z |
| Obs used |
59 |
| NEO |
- |
| M1 |
7.400 |
| K1 |
10.250 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2015-05-17T09:45:54.432000Z |
| Discovery magnitude (MPC) |
23.40 g |
| Discovery observatory (MPC) |
T09 · Subaru Telescope, Maunakea |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2014-08-27.0000000 |
| e |
1.00398018 |
| q (au) |
9.940926 |
| a (au) |
-2497.604954 |
| i (deg) |
159.939165 |
| Ω (om, deg) |
258.001127 |
| ω (w, deg) |
5.158803 |
| M (ma, deg) |
0.004368 |
等級
散乱 + 全体線形
$$
M_a = (5.609 + 4.567\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
5.609 |
| n |
4.567 |
| gf |
0.937 |
| gb |
-1.000 |
| k |
1.000 |
| δ90 |
5.810 |
| 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) |
| 2026-03-26 00:00 |
10:33:30.16 |
+30:24:32.0 |
HIP 51652 |
21.22 |
| 2026-03-26 12:00 |
10:33:24.56 |
+30:24:45.3 |
HIP 51652 |
20.78 |
| 2026-03-27 00:00 |
10:33:18.98 |
+30:24:58.3 |
HIP 51652 |
20.42 |
| 2026-03-27 12:00 |
10:33:13.43 |
+30:25:11.0 |
HIP 51652 |
20.12 |
| 2026-03-28 00:00 |
10:33:07.90 |
+30:25:23.3 |
HIP 51652 |
19.91 |
| 2026-03-28 12:00 |
10:33:02.40 |
+30:25:35.4 |
HIP 51652 |
19.76 |
| 2026-03-29 00:00 |
10:32:56.92 |
+30:25:47.1 |
HIP 51652 |
19.70 |
| 2026-03-29 12:00 |
10:32:51.47 |
+30:25:58.4 |
HIP 51652 |
19.71 |
| 2026-03-30 00:00 |
10:32:46.05 |
+30:26:09.5 |
HIP 51652 |
19.80 |
| 2026-03-30 12:00 |
10:32:40.65 |
+30:26:20.2 |
HIP 51652 |
19.96 |
| 2026-03-31 00:00 |
10:32:35.29 |
+30:26:30.5 |
HIP 51652 |
20.19 |
| 2026-03-31 12:00 |
10:32:29.95 |
+30:26:40.6 |
HIP 51652 |
20.49 |
| 2026-04-01 00:00 |
10:32:24.63 |
+30:26:50.3 |
HIP 51565 |
20.12 |
| 2026-04-01 12:00 |
10:32:19.35 |
+30:26:59.7 |
HIP 51487 |
19.45 |
| 2026-04-02 00:00 |
10:32:14.09 |
+30:27:08.8 |
HIP 51487 |
18.49 |
| 2026-04-02 12:00 |
10:32:08.87 |
+30:27:17.5 |
HIP 51487 |
17.57 |
| 2026-04-03 00:00 |
10:32:03.67 |
+30:27:25.9 |
HIP 51487 |
16.67 |
| 2026-04-03 12:00 |
10:31:58.51 |
+30:27:34.0 |
HIP 51487 |
15.80 |
| 2026-04-04 00:00 |
10:31:53.37 |
+30:27:41.8 |
HIP 51487 |
14.97 |
| 2026-04-04 12:00 |
10:31:48.26 |
+30:27:49.2 |
HIP 51487 |
14.18 |
| 2026-04-05 00:00 |
10:31:43.19 |
+30:27:56.3 |
HIP 51487 |
13.43 |
| 2026-04-05 12:00 |
10:31:38.14 |
+30:28:03.1 |
HIP 51487 |
12.74 |
| 2026-04-06 00:00 |
10:31:33.13 |
+30:28:09.6 |
HIP 51487 |
12.11 |
| 2026-04-06 12:00 |
10:31:28.14 |
+30:28:15.7 |
HIP 51487 |
11.54 |
| 2026-04-07 00:00 |
10:31:23.19 |
+30:28:21.5 |
HIP 51487 |
11.05 |
| 2026-04-07 12:00 |
10:31:18.27 |
+30:28:27.0 |
HIP 51487 |
10.65 |
| 2026-04-08 00:00 |
10:31:13.39 |
+30:28:32.2 |
HIP 51487 |
10.33 |
| 2026-04-08 12:00 |
10:31:08.54 |
+30:28:37.0 |
HIP 51487 |
10.12 |
| 2026-04-09 00:00 |
10:31:03.71 |
+30:28:41.5 |
HIP 51487 |
10.00 |
| 2026-04-09 12:00 |
10:30:58.93 |
+30:28:45.7 |
HIP 51487 |
9.99 |
| 2026-04-10 00:00 |
10:30:54.17 |
+30:28:49.6 |
HIP 51487 |
10.08 |
| 2026-04-10 12:00 |
10:30:49.45 |
+30:28:53.1 |
HIP 51487 |
10.26 |
| 2026-04-11 00:00 |
10:30:44.77 |
+30:28:56.3 |
HIP 51487 |
10.53 |
| 2026-04-11 12:00 |
10:30:40.12 |
+30:28:59.2 |
HIP 51487 |
10.89 |
| 2026-04-12 00:00 |
10:30:35.50 |
+30:29:01.8 |
HIP 51487 |
11.31 |
| 2026-04-12 12:00 |
10:30:30.92 |
+30:29:04.1 |
HIP 51487 |
11.79 |
| 2026-04-13 00:00 |
10:30:26.37 |
+30:29:06.0 |
HIP 51487 |
12.33 |
| 2026-04-13 12:00 |
10:30:21.86 |
+30:29:07.6 |
HIP 51487 |
12.91 |
| 2026-04-14 00:00 |
10:30:17.39 |
+30:29:08.9 |
HIP 51487 |
13.52 |
| 2026-04-14 12:00 |
10:30:12.95 |
+30:29:09.9 |
HIP 51487 |
14.17 |
| 2026-04-15 00:00 |
10:30:08.54 |
+30:29:10.6 |
HIP 51487 |
14.84 |
| 2026-04-15 12:00 |
10:30:04.18 |
+30:29:11.0 |
HIP 51487 |
15.53 |
| 2026-04-16 00:00 |
10:29:59.85 |
+30:29:11.0 |
HIP 51487 |
16.23 |