C/2018 C2 (Lemmon)
メタデータ
| 項目 |
値 |
| Designation |
C/2018 C2 (Lemmon) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2018-06-02T05:22:27.024960Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:41Z |
| Obs used |
1672 |
| NEO |
- |
| M1 |
7.600 |
| K1 |
26.500 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2018-02-05T13:13:03.072000Z |
| Discovery magnitude (MPC) |
19.60 G |
| Discovery observatory (MPC) |
G96 · Mt. Lemmon Survey |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2018-05-20.0000000 |
| e |
1.00180656 |
| q (au) |
1.956513 |
| a (au) |
-1083.006061 |
| i (deg) |
34.453393 |
| Ω (om, deg) |
91.139716 |
| ω (w, deg) |
134.138488 |
| M (ma, deg) |
-0.000366 |
等級
散乱 + 全体線形
$$
M_a = (10.243 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
10.243 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.998 |
| 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 |
| 2018-01-28 |
2018-06-01 |
+12.3467 |
-3.481 |
| 2018-06-02 |
2018-10-27 |
-13.9723 |
+3.855 |
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) |
| 2026-02-03 00:00 |
01:24:42.32 |
-27:16:54.0 |
HIP 6488 |
18.22 |
| 2026-02-03 12:00 |
01:24:45.10 |
-27:15:52.1 |
HIP 6488 |
18.63 |
| 2026-02-04 00:00 |
01:24:47.93 |
-27:14:50.3 |
HIP 6688 |
18.35 |
| 2026-02-04 12:00 |
01:24:50.80 |
-27:13:48.4 |
HIP 6688 |
17.22 |
| 2026-02-05 00:00 |
01:24:53.72 |
-27:12:46.6 |
HIP 6688 |
16.09 |
| 2026-02-05 12:00 |
01:24:56.68 |
-27:11:44.8 |
HIP 6688 |
14.98 |
| 2026-02-06 00:00 |
01:24:59.69 |
-27:10:43.0 |
HIP 6688 |
13.87 |
| 2026-02-06 12:00 |
01:25:02.74 |
-27:09:41.2 |
HIP 6688 |
12.77 |
| 2026-02-07 00:00 |
01:25:05.84 |
-27:08:39.4 |
HIP 6688 |
11.69 |
| 2026-02-07 12:00 |
01:25:08.99 |
-27:07:37.6 |
HIP 6688 |
10.64 |
| 2026-02-08 00:00 |
01:25:12.17 |
-27:06:35.9 |
HIP 6688 |
9.63 |
| 2026-02-08 12:00 |
01:25:15.41 |
-27:05:34.2 |
HIP 6688 |
8.66 |
| 2026-02-09 00:00 |
01:25:18.68 |
-27:04:32.5 |
HIP 6688 |
7.77 |
| 2026-02-09 12:00 |
01:25:22.00 |
-27:03:30.9 |
HIP 6688 |
6.99 |
| 2026-02-10 00:00 |
01:25:25.36 |
-27:02:29.3 |
HIP 6688 |
6.35 |
| 2026-02-10 12:00 |
01:25:28.77 |
-27:01:27.8 |
HIP 6688 |
5.91 |
| 2026-02-11 00:00 |
01:25:32.22 |
-27:00:26.3 |
HIP 6688 |
5.72 |
| 2026-02-11 12:00 |
01:25:35.71 |
-26:59:24.9 |
HIP 6688 |
5.80 |
| 2026-02-12 00:00 |
01:25:39.24 |
-26:58:23.5 |
HIP 6688 |
6.15 |
| 2026-02-12 12:00 |
01:25:42.82 |
-26:57:22.2 |
HIP 6688 |
6.73 |
| 2026-02-13 00:00 |
01:25:46.44 |
-26:56:21.0 |
HIP 6688 |
7.49 |
| 2026-02-13 12:00 |
01:25:50.10 |
-26:55:19.8 |
HIP 6688 |
8.38 |
| 2026-02-14 00:00 |
01:25:53.80 |
-26:54:18.7 |
HIP 6688 |
9.37 |
| 2026-02-14 12:00 |
01:25:57.54 |
-26:53:17.7 |
HIP 6688 |
10.42 |
| 2026-02-15 00:00 |
01:26:01.32 |
-26:52:16.7 |
HIP 6688 |
11.53 |
| 2026-02-15 12:00 |
01:26:05.14 |
-26:51:15.9 |
HIP 6688 |
12.69 |
| 2026-02-16 00:00 |
01:26:09.00 |
-26:50:15.1 |
HIP 6688 |
13.87 |
| 2026-02-16 12:00 |
01:26:12.90 |
-26:49:14.5 |
HIP 6688 |
15.08 |
| 2026-02-17 00:00 |
01:26:16.85 |
-26:48:13.9 |
HIP 6688 |
16.31 |
| 2026-02-17 12:00 |
01:26:20.83 |
-26:47:13.4 |
HIP 6688 |
17.55 |
| 2026-02-18 00:00 |
01:26:24.85 |
-26:46:13.0 |
HIP 6688 |
18.82 |
| 2026-02-18 12:00 |
01:26:28.90 |
-26:45:12.8 |
HIP 6688 |
20.09 |
| 2026-02-19 00:00 |
01:26:33.00 |
-26:44:12.6 |
HIP 6688 |
21.38 |
| 2026-02-19 12:00 |
01:26:37.14 |
-26:43:12.6 |
HIP 6664 |
21.61 |
| 2026-02-20 00:00 |
01:26:41.31 |
-26:42:12.7 |
HIP 6664 |
21.57 |
| 2026-02-20 12:00 |
01:26:45.52 |
-26:41:12.9 |
HIP 6664 |
21.62 |
| 2026-02-21 00:00 |
01:26:49.76 |
-26:40:13.2 |
HIP 6664 |
21.76 |
| 2026-02-21 12:00 |
01:26:54.05 |
-26:39:13.7 |
HIP 6664 |
22.00 |
| 2026-02-22 00:00 |
01:26:58.36 |
-26:38:14.3 |
HIP 6664 |
22.33 |
| 2026-02-22 12:00 |
01:27:02.72 |
-26:37:15.0 |
HIP 6664 |
22.74 |
| 2026-02-23 00:00 |
01:27:07.11 |
-26:36:15.9 |
HIP 6895 |
22.62 |
| 2026-02-23 12:00 |
01:27:11.53 |
-26:35:17.0 |
HIP 6895 |
21.51 |
| 2026-02-24 00:00 |
01:27:15.99 |
-26:34:18.1 |
HIP 6895 |
20.44 |