メタデータ
| 項目 |
値 |
| Designation |
C/2019 T2 (Lemmon) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2021-04-22T06:32:53.350080Z |
| Orbit solution date (soln_date, UTC) |
2023-08-06T18:12:27Z |
| Obs used |
187 |
| NEO |
- |
| M1 |
12.700 |
| K1 |
5.750 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2019-10-09T03:16:41.376000Z |
| Discovery magnitude (MPC) |
20.60 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) |
2021-02-26.0000000 |
| e |
0.99872185 |
| q (au) |
2.645893 |
| a (au) |
2070.091183 |
| i (deg) |
111.488095 |
| Ω (om, deg) |
155.641811 |
| ω (w, deg) |
239.386315 |
| M (ma, deg) |
359.999422 |
等級
散乱 + 全体線形
$$
M_a = (11.950 + 3.858\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
11.950 |
| n |
3.858 |
| gf |
1.000 |
| gb |
-0.704 |
| k |
0.800 |
| 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 |
| 2019-08-26 |
2019-11-30 |
+22.3715 |
-17.071 |
| 2019-11-30 |
2020-07-16 |
-0.1476 |
-0.346 |
| 2020-07-16 |
2020-10-26 |
-4.8324 |
+2.665 |
| 2020-10-26 |
2021-04-11 |
-2.5155 |
+1.291 |
| 2021-05-22 |
2022-01-22 |
-5.7468 |
+3.701 |
| 2022-01-22 |
2023-06-14 |
+4.9021 |
-2.908 |
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 |
10:22:38.52 |
+19:02:09.8 |
HIP 50848 |
7.51 |
| 2026-07-29 12:00 |
10:22:45.07 |
+19:01:44.0 |
HIP 50848 |
6.98 |
| 2026-07-30 00:00 |
10:22:51.63 |
+19:01:18.2 |
HIP 50848 |
6.79 |
| 2026-07-30 12:00 |
10:22:58.22 |
+19:00:52.4 |
HIP 50848 |
6.99 |
| 2026-07-31 00:00 |
10:23:04.83 |
+19:00:26.5 |
HIP 50848 |
7.53 |
| 2026-07-31 12:00 |
10:23:11.46 |
+19:00:00.7 |
HIP 50848 |
8.36 |
| 2026-08-01 00:00 |
10:23:18.11 |
+18:59:34.8 |
HIP 50848 |
9.40 |
| 2026-08-01 12:00 |
10:23:24.79 |
+18:59:08.9 |
HIP 50848 |
10.60 |
| 2026-08-02 00:00 |
10:23:31.48 |
+18:58:43.0 |
HIP 50848 |
11.90 |
| 2026-08-02 12:00 |
10:23:38.20 |
+18:58:17.1 |
HIP 50848 |
13.28 |
| 2026-08-03 00:00 |
10:23:44.93 |
+18:57:51.2 |
HIP 50848 |
14.72 |
| 2026-08-03 12:00 |
10:23:51.68 |
+18:57:25.3 |
HIP 50848 |
16.20 |
| 2026-08-04 00:00 |
10:23:58.46 |
+18:56:59.4 |
HIP 50848 |
17.72 |
| 2026-08-04 12:00 |
10:24:05.25 |
+18:56:33.5 |
HIP 50848 |
19.26 |
| 2026-08-05 00:00 |
10:24:12.06 |
+18:56:07.7 |
HIP 50848 |
20.83 |
| 2026-08-05 12:00 |
10:24:18.89 |
+18:55:41.8 |
HIP 50848 |
22.41 |
| 2026-08-06 00:00 |
10:24:25.73 |
+18:55:15.9 |
HIP 50936 |
23.15 |
| 2026-08-06 12:00 |
10:24:32.60 |
+18:54:50.1 |
HIP 50936 |
23.02 |
| 2026-08-07 00:00 |
10:24:39.48 |
+18:54:24.2 |
HIP 50936 |
23.00 |
| 2026-08-07 12:00 |
10:24:46.37 |
+18:53:58.4 |
HIP 50936 |
23.12 |
| 2026-08-08 00:00 |
10:24:53.28 |
+18:53:32.6 |
HIP 50936 |
23.35 |
| 2026-08-08 12:00 |
10:25:00.21 |
+18:53:06.9 |
HIP 50936 |
23.71 |
| 2026-08-09 00:00 |
10:25:07.15 |
+18:52:41.1 |
HIP 50936 |
24.18 |
| 2026-08-09 12:00 |
10:25:14.11 |
+18:52:15.4 |
HIP 50936 |
24.76 |
| 2026-08-10 00:00 |
10:25:21.08 |
+18:51:49.8 |
HIP 50936 |
25.45 |
| 2026-08-10 12:00 |
10:25:28.07 |
+18:51:24.1 |
HIP 50936 |
26.23 |
| 2026-08-11 00:00 |
10:25:35.07 |
+18:50:58.5 |
HIP 50936 |
27.10 |
| 2026-08-11 12:00 |
10:25:42.08 |
+18:50:33.0 |
HIP 50936 |
28.05 |
| 2026-08-12 00:00 |
10:25:49.11 |
+18:50:07.5 |
HIP 50936 |
29.08 |
| 2026-08-12 12:00 |
10:25:56.14 |
+18:49:42.0 |
HIP 50936 |
30.17 |
| 2026-08-13 00:00 |
10:26:03.19 |
+18:49:16.6 |
HIP 51241 |
30.60 |
| 2026-08-13 12:00 |
10:26:10.25 |
+18:48:51.3 |
HIP 51241 |
28.92 |
| 2026-08-14 00:00 |
10:26:17.32 |
+18:48:26.0 |
HIP 51241 |
27.24 |
| 2026-08-14 12:00 |
10:26:24.40 |
+18:48:00.7 |
HIP 51241 |
25.57 |
| 2026-08-15 00:00 |
10:26:31.49 |
+18:47:35.6 |
HIP 51241 |
23.90 |
| 2026-08-15 12:00 |
10:26:38.59 |
+18:47:10.5 |
HIP 51241 |
22.25 |
| 2026-08-16 00:00 |
10:26:45.70 |
+18:46:45.4 |
HIP 51241 |
20.60 |
| 2026-08-16 12:00 |
10:26:52.82 |
+18:46:20.5 |
HIP 51241 |
18.97 |
| 2026-08-17 00:00 |
10:26:59.94 |
+18:45:55.6 |
HIP 51241 |
17.36 |
| 2026-08-17 12:00 |
10:27:07.07 |
+18:45:30.7 |
HIP 51241 |
15.78 |
| 2026-08-18 00:00 |
10:27:14.21 |
+18:45:06.0 |
HIP 51241 |
14.23 |
| 2026-08-18 12:00 |
10:27:21.36 |
+18:44:41.3 |
HIP 51241 |
12.73 |
| 2026-08-19 00:00 |
10:27:28.51 |
+18:44:16.8 |
HIP 51241 |
11.30 |