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 · 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 |
+22.3714 |
-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) |
| 2026-05-12 00:00 |
10:14:21.82 |
+19:37:03.1 |
HIP 50223 |
31.59 |
| 2026-05-12 12:00 |
10:14:20.40 |
+19:37:12.0 |
HIP 50223 |
31.85 |
| 2026-05-13 00:00 |
10:14:19.06 |
+19:37:20.5 |
HIP 50223 |
32.09 |
| 2026-05-13 12:00 |
10:14:17.78 |
+19:37:28.7 |
HIP 50223 |
32.33 |
| 2026-05-14 00:00 |
10:14:16.58 |
+19:37:36.4 |
HIP 50223 |
32.56 |
| 2026-05-14 12:00 |
10:14:15.44 |
+19:37:43.7 |
HIP 50223 |
32.77 |
| 2026-05-15 00:00 |
10:14:14.38 |
+19:37:50.6 |
HIP 50223 |
32.97 |
| 2026-05-15 12:00 |
10:14:13.39 |
+19:37:57.1 |
HIP 50223 |
33.17 |
| 2026-05-16 00:00 |
10:14:12.47 |
+19:38:03.3 |
HIP 50223 |
33.34 |
| 2026-05-16 12:00 |
10:14:11.61 |
+19:38:09.0 |
HIP 50223 |
33.51 |
| 2026-05-17 00:00 |
10:14:10.83 |
+19:38:14.3 |
HIP 50223 |
33.67 |
| 2026-05-17 12:00 |
10:14:10.12 |
+19:38:19.3 |
HIP 50223 |
33.81 |
| 2026-05-18 00:00 |
10:14:09.48 |
+19:38:23.8 |
HIP 50223 |
33.94 |
| 2026-05-18 12:00 |
10:14:08.91 |
+19:38:28.0 |
HIP 50223 |
34.06 |
| 2026-05-19 00:00 |
10:14:08.41 |
+19:38:31.7 |
HIP 50223 |
34.17 |
| 2026-05-19 12:00 |
10:14:07.97 |
+19:38:35.1 |
HIP 50223 |
34.26 |
| 2026-05-20 00:00 |
10:14:07.61 |
+19:38:38.1 |
HIP 50223 |
34.34 |
| 2026-05-20 12:00 |
10:14:07.32 |
+19:38:40.8 |
HIP 50223 |
34.41 |
| 2026-05-21 00:00 |
10:14:07.09 |
+19:38:43.0 |
HIP 50223 |
34.47 |
| 2026-05-21 12:00 |
10:14:06.94 |
+19:38:44.9 |
HIP 50223 |
34.51 |
| 2026-05-22 00:00 |
10:14:06.85 |
+19:38:46.4 |
HIP 50223 |
34.54 |
| 2026-05-22 12:00 |
10:14:06.83 |
+19:38:47.6 |
HIP 50223 |
34.56 |
| 2026-05-23 00:00 |
10:14:06.88 |
+19:38:48.3 |
HIP 50223 |
34.57 |
| 2026-05-23 12:00 |
10:14:07.00 |
+19:38:48.8 |
HIP 50223 |
34.56 |
| 2026-05-24 00:00 |
10:14:07.19 |
+19:38:48.8 |
HIP 50223 |
34.55 |
| 2026-05-24 12:00 |
10:14:07.44 |
+19:38:48.5 |
HIP 50223 |
34.52 |
| 2026-05-25 00:00 |
10:14:07.76 |
+19:38:47.9 |
HIP 50223 |
34.48 |
| 2026-05-25 12:00 |
10:14:08.15 |
+19:38:46.9 |
HIP 50223 |
34.42 |
| 2026-05-26 00:00 |
10:14:08.61 |
+19:38:45.5 |
HIP 50223 |
34.36 |
| 2026-05-26 12:00 |
10:14:09.13 |
+19:38:43.8 |
HIP 50223 |
34.28 |
| 2026-05-27 00:00 |
10:14:09.72 |
+19:38:41.7 |
HIP 50223 |
34.19 |
| 2026-05-27 12:00 |
10:14:10.37 |
+19:38:39.3 |
HIP 50223 |
34.09 |
| 2026-05-28 00:00 |
10:14:11.09 |
+19:38:36.6 |
HIP 50223 |
33.98 |
| 2026-05-28 12:00 |
10:14:11.88 |
+19:38:33.5 |
HIP 50223 |
33.86 |
| 2026-05-29 00:00 |
10:14:12.73 |
+19:38:30.1 |
HIP 50223 |
33.73 |
| 2026-05-29 12:00 |
10:14:13.65 |
+19:38:26.4 |
HIP 50223 |
33.59 |
| 2026-05-30 00:00 |
10:14:14.63 |
+19:38:22.3 |
HIP 50223 |
33.44 |
| 2026-05-30 12:00 |
10:14:15.68 |
+19:38:17.9 |
HIP 50223 |
33.28 |
| 2026-05-31 00:00 |
10:14:16.79 |
+19:38:13.2 |
HIP 50223 |
33.11 |
| 2026-05-31 12:00 |
10:14:17.96 |
+19:38:08.1 |
HIP 50223 |
32.93 |
| 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 |