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) |
| 2026-05-12 00:00 |
00:54:33.67 |
-03:33:25.2 |
HIP 4374 |
24.60 |
| 2026-05-12 12:00 |
00:54:38.32 |
-03:33:03.6 |
HIP 4374 |
23.73 |
| 2026-05-13 00:00 |
00:54:42.93 |
-03:32:42.4 |
HIP 4374 |
22.90 |
| 2026-05-13 12:00 |
00:54:47.50 |
-03:32:21.6 |
HIP 4374 |
22.11 |
| 2026-05-14 00:00 |
00:54:52.03 |
-03:32:01.1 |
HIP 4374 |
21.36 |
| 2026-05-14 12:00 |
00:54:56.52 |
-03:31:41.0 |
HIP 4374 |
20.66 |
| 2026-05-15 00:00 |
00:55:00.96 |
-03:31:21.4 |
HIP 4374 |
20.00 |
| 2026-05-15 12:00 |
00:55:05.37 |
-03:31:02.1 |
HIP 4374 |
19.39 |
| 2026-05-16 00:00 |
00:55:09.74 |
-03:30:43.2 |
HIP 4374 |
18.84 |
| 2026-05-16 12:00 |
00:55:14.06 |
-03:30:24.8 |
HIP 4374 |
18.33 |
| 2026-05-17 00:00 |
00:55:18.34 |
-03:30:06.7 |
HIP 4374 |
17.89 |
| 2026-05-17 12:00 |
00:55:22.58 |
-03:29:49.1 |
HIP 4374 |
17.51 |
| 2026-05-18 00:00 |
00:55:26.78 |
-03:29:31.8 |
HIP 4374 |
17.19 |
| 2026-05-18 12:00 |
00:55:30.93 |
-03:29:15.0 |
HIP 4374 |
16.93 |
| 2026-05-19 00:00 |
00:55:35.04 |
-03:28:58.5 |
HIP 4374 |
16.73 |
| 2026-05-19 12:00 |
00:55:39.11 |
-03:28:42.5 |
HIP 4374 |
16.60 |
| 2026-05-20 00:00 |
00:55:43.12 |
-03:28:26.9 |
HIP 4374 |
16.53 |
| 2026-05-20 12:00 |
00:55:47.10 |
-03:28:11.7 |
HIP 4374 |
16.52 |
| 2026-05-21 00:00 |
00:55:51.03 |
-03:27:56.9 |
HIP 4374 |
16.56 |
| 2026-05-21 12:00 |
00:55:54.91 |
-03:27:42.5 |
HIP 4374 |
16.67 |
| 2026-05-22 00:00 |
00:55:58.74 |
-03:27:28.6 |
HIP 4374 |
16.82 |
| 2026-05-22 12:00 |
00:56:02.53 |
-03:27:15.1 |
HIP 4374 |
17.03 |
| 2026-05-23 00:00 |
00:56:06.28 |
-03:27:02.0 |
HIP 4374 |
17.28 |
| 2026-05-23 12:00 |
00:56:09.97 |
-03:26:49.3 |
HIP 4374 |
17.57 |
| 2026-05-24 00:00 |
00:56:13.62 |
-03:26:37.0 |
HIP 4374 |
17.89 |
| 2026-05-24 12:00 |
00:56:17.22 |
-03:26:25.2 |
HIP 4374 |
18.25 |
| 2026-05-25 00:00 |
00:56:20.76 |
-03:26:13.8 |
HIP 4374 |
18.64 |
| 2026-05-25 12:00 |
00:56:24.27 |
-03:26:02.8 |
HIP 4374 |
19.05 |
| 2026-05-26 00:00 |
00:56:27.72 |
-03:25:52.2 |
HIP 4374 |
19.48 |
| 2026-05-26 12:00 |
00:56:31.12 |
-03:25:42.1 |
HIP 4374 |
19.93 |
| 2026-05-27 00:00 |
00:56:34.47 |
-03:25:32.4 |
HIP 4374 |
20.40 |
| 2026-05-27 12:00 |
00:56:37.78 |
-03:25:23.2 |
HIP 4374 |
20.88 |
| 2026-05-28 00:00 |
00:56:41.03 |
-03:25:14.3 |
HIP 4374 |
21.37 |
| 2026-05-28 12:00 |
00:56:44.23 |
-03:25:05.9 |
HIP 4374 |
21.87 |
| 2026-05-29 00:00 |
00:56:47.38 |
-03:24:57.9 |
HIP 4374 |
22.37 |
| 2026-05-29 12:00 |
00:56:50.48 |
-03:24:50.4 |
HIP 4374 |
22.87 |
| 2026-05-30 00:00 |
00:56:53.52 |
-03:24:43.3 |
HIP 4374 |
23.38 |
| 2026-05-30 12:00 |
00:56:56.52 |
-03:24:36.6 |
HIP 4374 |
23.89 |
| 2026-05-31 00:00 |
00:56:59.46 |
-03:24:30.4 |
HIP 4374 |
24.40 |
| 2026-05-31 12:00 |
00:57:02.35 |
-03:24:24.6 |
HIP 4374 |
24.91 |
| 2026-06-01 00:00 |
00:57:05.18 |
-03:24:19.3 |
HIP 4374 |
25.41 |
| 2026-06-01 12:00 |
00:57:07.97 |
-03:24:14.4 |
HIP 4374 |
25.91 |
| 2026-06-02 00:00 |
00:57:10.70 |
-03:24:09.9 |
HIP 4374 |
26.40 |