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) |
| 2026-06-01 00:00 |
10:14:19.20 |
+19:38:02.7 |
HIP 50223 |
32.74 |
| 2026-06-01 12:00 |
10:14:20.51 |
+19:37:57.1 |
HIP 50223 |
32.54 |
| 2026-06-02 00:00 |
10:14:21.88 |
+19:37:51.0 |
HIP 50223 |
32.33 |
| 2026-06-02 12:00 |
10:14:23.31 |
+19:37:44.7 |
HIP 50223 |
32.12 |
| 2026-06-03 00:00 |
10:14:24.80 |
+19:37:38.1 |
HIP 50223 |
31.90 |
| 2026-06-03 12:00 |
10:14:26.36 |
+19:37:31.1 |
HIP 50223 |
31.67 |
| 2026-06-04 00:00 |
10:14:27.98 |
+19:37:23.9 |
HIP 50223 |
31.44 |
| 2026-06-04 12:00 |
10:14:29.67 |
+19:37:16.3 |
HIP 50223 |
31.20 |
| 2026-06-05 00:00 |
10:14:31.41 |
+19:37:08.4 |
HIP 50223 |
30.96 |
| 2026-06-05 12:00 |
10:14:33.22 |
+19:37:00.2 |
HIP 50223 |
30.71 |
| 2026-06-06 00:00 |
10:14:35.09 |
+19:36:51.8 |
HIP 50223 |
30.45 |
| 2026-06-06 12:00 |
10:14:37.02 |
+19:36:43.0 |
HIP 50223 |
30.20 |
| 2026-06-07 00:00 |
10:14:39.01 |
+19:36:33.9 |
HIP 50223 |
29.94 |
| 2026-06-07 12:00 |
10:14:41.07 |
+19:36:24.6 |
HIP 50223 |
29.67 |
| 2026-06-08 00:00 |
10:14:43.18 |
+19:36:14.9 |
HIP 50223 |
29.41 |
| 2026-06-08 12:00 |
10:14:45.36 |
+19:36:05.0 |
HIP 50223 |
29.15 |
| 2026-06-09 00:00 |
10:14:47.59 |
+19:35:54.8 |
HIP 50223 |
28.89 |
| 2026-06-09 12:00 |
10:14:49.89 |
+19:35:44.2 |
HIP 50223 |
28.62 |
| 2026-06-10 00:00 |
10:14:52.24 |
+19:35:33.5 |
HIP 50223 |
28.37 |
| 2026-06-10 12:00 |
10:14:54.66 |
+19:35:22.4 |
HIP 50223 |
28.11 |
| 2026-06-11 00:00 |
10:14:57.13 |
+19:35:11.0 |
HIP 50223 |
27.86 |
| 2026-06-11 12:00 |
10:14:59.67 |
+19:34:59.4 |
HIP 50223 |
27.61 |
| 2026-06-12 00:00 |
10:15:02.26 |
+19:34:47.5 |
HIP 50223 |
27.37 |
| 2026-06-12 12:00 |
10:15:04.91 |
+19:34:35.3 |
HIP 50223 |
27.14 |
| 2026-06-13 00:00 |
10:15:07.62 |
+19:34:22.9 |
HIP 50223 |
26.92 |
| 2026-06-13 12:00 |
10:15:10.39 |
+19:34:10.2 |
HIP 50223 |
26.71 |
| 2026-06-14 00:00 |
10:15:13.21 |
+19:33:57.2 |
HIP 50223 |
26.52 |
| 2026-06-14 12:00 |
10:15:16.10 |
+19:33:44.0 |
HIP 50223 |
26.33 |
| 2026-06-15 00:00 |
10:15:19.04 |
+19:33:30.5 |
HIP 50223 |
26.16 |
| 2026-06-15 12:00 |
10:15:22.03 |
+19:33:16.8 |
HIP 50223 |
26.01 |
| 2026-06-16 00:00 |
10:15:25.09 |
+19:33:02.8 |
HIP 50223 |
25.88 |
| 2026-06-16 12:00 |
10:15:28.20 |
+19:32:48.6 |
HIP 50223 |
25.77 |
| 2026-06-17 00:00 |
10:15:31.36 |
+19:32:34.1 |
HIP 50223 |
25.67 |
| 2026-06-17 12:00 |
10:15:34.58 |
+19:32:19.4 |
HIP 50223 |
25.60 |
| 2026-06-18 00:00 |
10:15:37.86 |
+19:32:04.4 |
HIP 50223 |
25.56 |
| 2026-06-18 12:00 |
10:15:41.19 |
+19:31:49.2 |
HIP 50223 |
25.54 |
| 2026-06-19 00:00 |
10:15:44.57 |
+19:31:33.8 |
HIP 50223 |
25.55 |
| 2026-06-19 12:00 |
10:15:48.01 |
+19:31:18.1 |
HIP 50223 |
25.58 |
| 2026-06-20 00:00 |
10:15:51.50 |
+19:31:02.2 |
HIP 50223 |
25.65 |
| 2026-06-20 12:00 |
10:15:55.05 |
+19:30:46.1 |
HIP 50223 |
25.75 |
| 2026-06-21 00:00 |
10:15:58.64 |
+19:30:29.7 |
HIP 50223 |
25.88 |
| 2026-06-21 12:00 |
10:16:02.29 |
+19:30:13.2 |
HIP 50223 |
26.04 |
| 2026-06-22 00:00 |
10:16:05.99 |
+19:29:56.4 |
HIP 50223 |
26.23 |