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 · 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 |
0.931 |
| 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) |
| 2026-03-26 00:00 |
00:45:27.13 |
-04:30:43.0 |
HIP 3552 |
7.08 |
| 2026-03-26 12:00 |
00:45:33.41 |
-04:29:55.4 |
HIP 3552 |
8.17 |
| 2026-03-27 00:00 |
00:45:39.70 |
-04:29:07.9 |
HIP 3552 |
9.46 |
| 2026-03-27 12:00 |
00:45:45.99 |
-04:28:20.6 |
HIP 3552 |
10.88 |
| 2026-03-28 00:00 |
00:45:52.29 |
-04:27:33.5 |
HIP 3645 |
12.18 |
| 2026-03-28 12:00 |
00:45:58.59 |
-04:26:46.5 |
HIP 3645 |
10.52 |
| 2026-03-29 00:00 |
00:46:04.89 |
-04:25:59.7 |
HIP 3645 |
8.89 |
| 2026-03-29 12:00 |
00:46:11.19 |
-04:25:13.1 |
HIP 3645 |
7.32 |
| 2026-03-30 00:00 |
00:46:17.49 |
-04:24:26.6 |
HIP 3645 |
5.85 |
| 2026-03-30 12:00 |
00:46:23.80 |
-04:23:40.3 |
HIP 3645 |
4.59 |
| 2026-03-31 00:00 |
00:46:30.10 |
-04:22:54.2 |
HIP 3645 |
3.73 |
| 2026-03-31 12:00 |
00:46:36.41 |
-04:22:08.3 |
HIP 3645 |
3.60 |
| 2026-04-01 00:00 |
00:46:42.72 |
-04:21:22.5 |
HIP 3645 |
4.24 |
| 2026-04-01 12:00 |
00:46:49.02 |
-04:20:37.0 |
HIP 3645 |
5.40 |
| 2026-04-02 00:00 |
00:46:55.32 |
-04:19:51.6 |
HIP 3645 |
6.81 |
| 2026-04-02 12:00 |
00:47:01.63 |
-04:19:06.4 |
HIP 3645 |
8.35 |
| 2026-04-03 00:00 |
00:47:07.93 |
-04:18:21.4 |
HIP 3645 |
9.95 |
| 2026-04-03 12:00 |
00:47:14.22 |
-04:17:36.6 |
HIP 3645 |
11.58 |
| 2026-04-04 00:00 |
00:47:20.52 |
-04:16:52.0 |
HIP 3645 |
13.24 |
| 2026-04-04 12:00 |
00:47:26.81 |
-04:16:07.6 |
HIP 3645 |
14.92 |
| 2026-04-05 00:00 |
00:47:33.10 |
-04:15:23.4 |
HIP 3645 |
16.60 |
| 2026-04-05 12:00 |
00:47:39.38 |
-04:14:39.4 |
HIP 3645 |
18.29 |
| 2026-04-06 00:00 |
00:47:45.66 |
-04:13:55.6 |
HIP 3645 |
19.99 |
| 2026-04-06 12:00 |
00:47:51.93 |
-04:13:12.1 |
HIP 3645 |
21.69 |
| 2026-04-07 00:00 |
00:47:58.19 |
-04:12:28.7 |
HIP 3645 |
23.38 |
| 2026-04-07 12:00 |
00:48:04.45 |
-04:11:45.6 |
HIP 3645 |
25.08 |
| 2026-04-08 00:00 |
00:48:10.71 |
-04:11:02.6 |
HIP 3645 |
26.78 |
| 2026-04-08 12:00 |
00:48:16.95 |
-04:10:19.9 |
HIP 3746 |
27.80 |
| 2026-04-09 00:00 |
00:48:23.19 |
-04:09:37.5 |
HIP 3746 |
27.33 |
| 2026-04-09 12:00 |
00:48:29.42 |
-04:08:55.2 |
HIP 3746 |
26.96 |
| 2026-04-10 00:00 |
00:48:35.64 |
-04:08:13.2 |
HIP 3746 |
26.70 |
| 2026-04-10 12:00 |
00:48:41.85 |
-04:07:31.4 |
HIP 3746 |
26.55 |
| 2026-04-11 00:00 |
00:48:48.06 |
-04:06:49.9 |
HIP 3746 |
26.51 |
| 2026-04-11 12:00 |
00:48:54.25 |
-04:06:08.6 |
HIP 3746 |
26.58 |
| 2026-04-12 00:00 |
00:49:00.43 |
-04:05:27.5 |
HIP 3746 |
26.76 |
| 2026-04-12 12:00 |
00:49:06.60 |
-04:04:46.7 |
HIP 3746 |
27.04 |
| 2026-04-13 00:00 |
00:49:12.76 |
-04:04:06.1 |
HIP 3746 |
27.43 |
| 2026-04-13 12:00 |
00:49:18.91 |
-04:03:25.8 |
HIP 3746 |
27.91 |
| 2026-04-14 00:00 |
00:49:25.04 |
-04:02:45.7 |
HIP 3746 |
28.48 |
| 2026-04-14 12:00 |
00:49:31.17 |
-04:02:05.9 |
HIP 3746 |
29.14 |
| 2026-04-15 00:00 |
00:49:37.27 |
-04:01:26.4 |
HIP 3746 |
29.88 |
| 2026-04-15 12:00 |
00:49:43.37 |
-04:00:47.1 |
HIP 3746 |
30.69 |
| 2026-04-16 00:00 |
00:49:49.45 |
-04:00:08.0 |
HIP 4040 |
30.23 |