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) |
| 2026-09-20 00:00 |
00:41:06.55 |
-05:50:39.6 |
HIP 3313 |
29.05 |
| 2026-09-20 12:00 |
00:40:56.33 |
-05:51:42.6 |
HIP 3313 |
29.71 |
| 2026-09-21 00:00 |
00:40:46.10 |
-05:52:45.4 |
HIP 3313 |
30.61 |
| 2026-09-21 12:00 |
00:40:35.85 |
-05:53:48.2 |
HIP 3313 |
31.73 |
| 2026-09-22 00:00 |
00:40:25.59 |
-05:54:50.8 |
HIP 3313 |
33.04 |
| 2026-09-22 12:00 |
00:40:15.31 |
-05:55:53.2 |
HIP 3313 |
34.53 |
| 2026-09-23 00:00 |
00:40:05.03 |
-05:56:55.5 |
HIP 2980 |
32.00 |
| 2026-09-23 12:00 |
00:39:54.73 |
-05:57:57.7 |
HIP 2980 |
29.37 |
| 2026-09-24 00:00 |
00:39:44.42 |
-05:58:59.7 |
HIP 2980 |
26.75 |
| 2026-09-24 12:00 |
00:39:34.10 |
-06:00:01.5 |
HIP 2980 |
24.17 |
| 2026-09-25 00:00 |
00:39:23.77 |
-06:01:03.1 |
HIP 2980 |
21.64 |
| 2026-09-25 12:00 |
00:39:13.43 |
-06:02:04.6 |
HIP 2980 |
19.16 |
| 2026-09-26 00:00 |
00:39:03.08 |
-06:03:06.0 |
HIP 2980 |
16.77 |
| 2026-09-26 12:00 |
00:38:52.73 |
-06:04:07.1 |
HIP 2980 |
14.52 |
| 2026-09-27 00:00 |
00:38:42.37 |
-06:05:08.0 |
HIP 2980 |
12.47 |
| 2026-09-27 12:00 |
00:38:32.01 |
-06:06:08.8 |
HIP 2980 |
10.75 |
| 2026-09-28 00:00 |
00:38:21.64 |
-06:07:09.4 |
HIP 2980 |
9.53 |
| 2026-09-28 12:00 |
00:38:11.26 |
-06:08:09.7 |
HIP 2980 |
9.02 |
| 2026-09-29 00:00 |
00:38:00.89 |
-06:09:09.9 |
HIP 2980 |
9.34 |
| 2026-09-29 12:00 |
00:37:50.51 |
-06:10:09.8 |
HIP 2980 |
10.41 |
| 2026-09-30 00:00 |
00:37:40.13 |
-06:11:09.5 |
HIP 2919 |
11.58 |
| 2026-09-30 12:00 |
00:37:29.75 |
-06:12:09.0 |
HIP 2919 |
9.78 |
| 2026-10-01 00:00 |
00:37:19.37 |
-06:13:08.3 |
HIP 2919 |
8.51 |
| 2026-10-01 12:00 |
00:37:08.99 |
-06:14:07.4 |
HIP 2919 |
8.02 |
| 2026-10-02 00:00 |
00:36:58.61 |
-06:15:06.2 |
HIP 2919 |
8.46 |
| 2026-10-02 12:00 |
00:36:48.23 |
-06:16:04.7 |
HIP 2919 |
9.69 |
| 2026-10-03 00:00 |
00:36:37.86 |
-06:17:03.1 |
HIP 2919 |
11.46 |
| 2026-10-03 12:00 |
00:36:27.49 |
-06:18:01.1 |
HIP 2919 |
13.55 |
| 2026-10-04 00:00 |
00:36:17.13 |
-06:18:59.0 |
HIP 2785 |
15.49 |
| 2026-10-04 12:00 |
00:36:06.77 |
-06:19:56.5 |
HIP 2785 |
14.46 |
| 2026-10-05 00:00 |
00:35:56.42 |
-06:20:53.8 |
HIP 2785 |
13.91 |
| 2026-10-05 12:00 |
00:35:46.07 |
-06:21:50.8 |
HIP 2785 |
13.88 |
| 2026-10-06 00:00 |
00:35:35.73 |
-06:22:47.6 |
HIP 2785 |
14.38 |
| 2026-10-06 12:00 |
00:35:25.41 |
-06:23:44.0 |
HIP 2785 |
15.35 |
| 2026-10-07 00:00 |
00:35:15.09 |
-06:24:40.2 |
HIP 2710 |
13.13 |
| 2026-10-07 12:00 |
00:35:04.78 |
-06:25:36.1 |
HIP 2710 |
10.41 |
| 2026-10-08 00:00 |
00:34:54.49 |
-06:26:31.7 |
HIP 2710 |
7.72 |
| 2026-10-08 12:00 |
00:34:44.21 |
-06:27:26.9 |
HIP 2710 |
5.05 |
| 2026-10-09 00:00 |
00:34:33.94 |
-06:28:21.9 |
HIP 2710 |
2.50 |
| 2026-10-09 12:00 |
00:34:23.68 |
-06:29:16.6 |
HIP 2710 |
1.29 |
| 2026-10-10 00:00 |
00:34:13.44 |
-06:30:10.9 |
HIP 2710 |
3.42 |
| 2026-10-10 12:00 |
00:34:03.22 |
-06:31:04.9 |
HIP 2710 |
6.02 |
| 2026-10-11 00:00 |
00:33:53.01 |
-06:31:58.6 |
HIP 2710 |
8.68 |