メタデータ
| 項目 |
値 |
| Designation |
C/2021 C6 (Lemmon) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2021-11-13T08:19:46.225920Z |
| Orbit solution date (soln_date, UTC) |
2022-12-28T10:16:54Z |
| Obs used |
199 |
| NEO |
- |
| M1 |
15.600 |
| K1 |
4.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2021-02-07T10:22:20.006400Z |
| Discovery magnitude (MPC) |
20.86 G |
| Discovery observatory (MPC) |
G96 · University of Arizona Mt. Lemmon Survey |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2021-09-15.0000000 |
| e |
1.00185407 |
| q (au) |
3.271189 |
| a (au) |
-1764.328257 |
| i (deg) |
164.625857 |
| Ω (om, deg) |
332.155949 |
| ω (w, deg) |
203.567737 |
| M (ma, deg) |
-0.000789 |
等級
散乱 + 全体線形
$$
M_a = (15.001 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
15.001 |
| n |
2.000 |
| gf |
0.929 |
| gb |
-0.889 |
| k |
1.000 |
| 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 |
| 2021-01-23 |
2021-11-09 |
-4.1916 |
+2.446 |
| 2021-11-28 |
2022-12-15 |
+13.4351 |
-7.126 |
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) |
| 2026-07-29 00:00 |
00:55:21.01 |
-04:05:48.3 |
HIP 4345 |
8.11 |
| 2026-07-29 12:00 |
00:55:16.03 |
-04:06:35.3 |
HIP 4345 |
9.52 |
| 2026-07-30 00:00 |
00:55:10.97 |
-04:07:22.6 |
HIP 4345 |
10.96 |
| 2026-07-30 12:00 |
00:55:05.84 |
-04:08:10.3 |
HIP 4345 |
12.43 |
| 2026-07-31 00:00 |
00:55:00.65 |
-04:08:58.3 |
HIP 4345 |
13.92 |
| 2026-07-31 12:00 |
00:54:55.38 |
-04:09:46.8 |
HIP 4345 |
15.44 |
| 2026-08-01 00:00 |
00:54:50.05 |
-04:10:35.5 |
HIP 4345 |
16.98 |
| 2026-08-01 12:00 |
00:54:44.65 |
-04:11:24.6 |
HIP 4345 |
18.54 |
| 2026-08-02 00:00 |
00:54:39.17 |
-04:12:14.1 |
HIP 4345 |
20.11 |
| 2026-08-02 12:00 |
00:54:33.63 |
-04:13:04.0 |
HIP 4345 |
21.71 |
| 2026-08-03 00:00 |
00:54:28.02 |
-04:13:54.1 |
HIP 4207 |
21.14 |
| 2026-08-03 12:00 |
00:54:22.34 |
-04:14:44.6 |
HIP 4207 |
19.67 |
| 2026-08-04 00:00 |
00:54:16.60 |
-04:15:35.5 |
HIP 4207 |
18.21 |
| 2026-08-04 12:00 |
00:54:10.78 |
-04:16:26.7 |
HIP 4207 |
16.79 |
| 2026-08-05 00:00 |
00:54:04.90 |
-04:17:18.2 |
HIP 4207 |
15.40 |
| 2026-08-05 12:00 |
00:53:58.95 |
-04:18:10.1 |
HIP 4207 |
14.07 |
| 2026-08-06 00:00 |
00:53:52.93 |
-04:19:02.3 |
HIP 4207 |
12.83 |
| 2026-08-06 12:00 |
00:53:46.84 |
-04:19:54.8 |
HIP 4207 |
11.70 |
| 2026-08-07 00:00 |
00:53:40.69 |
-04:20:47.7 |
HIP 4207 |
10.74 |
| 2026-08-07 12:00 |
00:53:34.47 |
-04:21:40.8 |
HIP 4207 |
10.00 |
| 2026-08-08 00:00 |
00:53:28.18 |
-04:22:34.3 |
HIP 4207 |
9.54 |
| 2026-08-08 12:00 |
00:53:21.83 |
-04:23:28.1 |
HIP 4207 |
9.41 |
| 2026-08-09 00:00 |
00:53:15.41 |
-04:24:22.2 |
HIP 4207 |
9.64 |
| 2026-08-09 12:00 |
00:53:08.92 |
-04:25:16.6 |
HIP 4207 |
10.21 |
| 2026-08-10 00:00 |
00:53:02.37 |
-04:26:11.3 |
HIP 4207 |
11.07 |
| 2026-08-10 12:00 |
00:52:55.75 |
-04:27:06.3 |
HIP 4207 |
12.18 |
| 2026-08-11 00:00 |
00:52:49.07 |
-04:28:01.6 |
HIP 4207 |
13.48 |
| 2026-08-11 12:00 |
00:52:42.33 |
-04:28:57.2 |
HIP 4207 |
14.92 |
| 2026-08-12 00:00 |
00:52:35.52 |
-04:29:53.1 |
HIP 4207 |
16.47 |
| 2026-08-12 12:00 |
00:52:28.64 |
-04:30:49.3 |
HIP 4207 |
18.12 |
| 2026-08-13 00:00 |
00:52:21.70 |
-04:31:45.7 |
HIP 4207 |
19.83 |
| 2026-08-13 12:00 |
00:52:14.70 |
-04:32:42.4 |
HIP 4207 |
21.61 |
| 2026-08-14 00:00 |
00:52:07.64 |
-04:33:39.4 |
HIP 4207 |
23.43 |
| 2026-08-14 12:00 |
00:52:00.51 |
-04:34:36.6 |
HIP 4207 |
25.30 |
| 2026-08-15 00:00 |
00:51:53.32 |
-04:35:34.1 |
HIP 4207 |
27.20 |
| 2026-08-15 12:00 |
00:51:46.07 |
-04:36:31.8 |
HIP 3979 |
27.27 |
| 2026-08-16 00:00 |
00:51:38.76 |
-04:37:29.8 |
HIP 3979 |
25.81 |
| 2026-08-16 12:00 |
00:51:31.39 |
-04:38:28.0 |
HIP 3979 |
24.42 |
| 2026-08-17 00:00 |
00:51:23.96 |
-04:39:26.5 |
HIP 3979 |
23.13 |
| 2026-08-17 12:00 |
00:51:16.47 |
-04:40:25.2 |
HIP 3979 |
21.97 |
| 2026-08-18 00:00 |
00:51:08.91 |
-04:41:24.2 |
HIP 3979 |
20.94 |
| 2026-08-18 12:00 |
00:51:01.30 |
-04:42:23.3 |
HIP 3979 |
20.09 |
| 2026-08-19 00:00 |
00:50:53.64 |
-04:43:22.7 |
HIP 3979 |
19.43 |