메타데이터
| 항목 |
값 |
| Designation |
C/2021 U4 (Leonard) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2021-12-21T23:21:30.078720Z |
| Orbit solution date (soln_date, UTC) |
2025-01-14T17:42:12Z |
| Obs used |
37 |
| NEO |
- |
| M1 |
18.800 |
| K1 |
4.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2021-10-31T07:11:48.940800Z |
| Discovery magnitude (MPC) |
19.87 G |
| Discovery observatory (MPC) |
G96 · Mt. Lemmon Survey |
Osculating 궤도요소
| 항목 |
값 |
| Epoch (epoch_cal, TDB) |
2021-10-27.0000000 |
| e |
0.95934634 |
| q (au) |
1.787292 |
| a (au) |
43.963864 |
| i (deg) |
152.875238 |
| Ω (om, deg) |
241.798913 |
| ω (w, deg) |
237.287717 |
| M (ma, deg) |
359.810748 |
밝기
산란 + 전체 선형
$$
M_a = (19.361 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
모델 상수
| 항목 |
값 |
| H0 |
19.361 |
| n |
2.000 |
| gf |
0.990 |
| gb |
-0.500 |
| k |
0.800 |
| δ90 |
5.672 |
| 파라미터 |
기호 |
범위 |
설명 |
| 태양·지구거리 1 AU에서의 절대등급 |
H0 |
-5 to 20 |
혜성의 고유 밝기 |
| 광도 기울기 파라미터 |
n |
2 to 6 |
태양거리 변화에 따른 밝기 변화율 |
| 전방 산란 비대칭 계수 |
gf |
0.8 to 1 |
전방 산란의 강도 |
| 후방 산란 비대칭 계수 |
gb |
-1 to -0.5 |
후방 산란의 강도 |
| 분할 계수 |
k |
0.8 to 1 |
전·후방 산란 기여도 비율 |
| 먼지/가스 밝기 비 |
δ90 |
1 to 10 |
코마에서 먼지 산란 대비 가스 방출의 상대 기여 |
참고: EPSC-DPS2025-160
천체력
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
15:20:31.05 |
-10:21:16.3 |
HIP 75136 |
25.47 |
| 2026-03-26 12:00 |
15:20:23.27 |
-10:20:21.0 |
HIP 75136 |
27.18 |
| 2026-03-27 00:00 |
15:20:15.43 |
-10:19:25.5 |
HIP 75136 |
28.96 |
| 2026-03-27 12:00 |
15:20:07.52 |
-10:18:29.9 |
HIP 75136 |
30.79 |
| 2026-03-28 00:00 |
15:19:59.55 |
-10:17:34.1 |
HIP 75136 |
32.67 |
| 2026-03-28 12:00 |
15:19:51.51 |
-10:16:38.2 |
HIP 75136 |
34.60 |
| 2026-03-29 00:00 |
15:19:43.42 |
-10:15:42.1 |
HIP 74908 |
33.67 |
| 2026-03-29 12:00 |
15:19:35.26 |
-10:14:45.9 |
HIP 74908 |
31.85 |
| 2026-03-30 00:00 |
15:19:27.04 |
-10:13:49.6 |
HIP 74908 |
30.06 |
| 2026-03-30 12:00 |
15:19:18.76 |
-10:12:53.1 |
HIP 74908 |
28.33 |
| 2026-03-31 00:00 |
15:19:10.42 |
-10:11:56.5 |
HIP 74908 |
26.67 |
| 2026-03-31 12:00 |
15:19:02.03 |
-10:10:59.8 |
HIP 74908 |
25.10 |
| 2026-04-01 00:00 |
15:18:53.57 |
-10:10:03.0 |
HIP 74908 |
23.63 |
| 2026-04-01 12:00 |
15:18:45.06 |
-10:09:06.0 |
HIP 74908 |
22.31 |
| 2026-04-02 00:00 |
15:18:36.49 |
-10:08:08.9 |
HIP 74908 |
21.14 |
| 2026-04-02 12:00 |
15:18:27.86 |
-10:07:11.8 |
HIP 74908 |
20.17 |
| 2026-04-03 00:00 |
15:18:19.18 |
-10:06:14.5 |
HIP 74908 |
19.44 |
| 2026-04-03 12:00 |
15:18:10.44 |
-10:05:17.1 |
HIP 74908 |
18.97 |
| 2026-04-04 00:00 |
15:18:01.65 |
-10:04:19.6 |
HIP 74908 |
18.79 |
| 2026-04-04 12:00 |
15:17:52.80 |
-10:03:22.0 |
HIP 74908 |
18.92 |
| 2026-04-05 00:00 |
15:17:43.90 |
-10:02:24.4 |
HIP 74908 |
19.34 |
| 2026-04-05 12:00 |
15:17:34.95 |
-10:01:26.6 |
HIP 74908 |
20.05 |
| 2026-04-06 00:00 |
15:17:25.94 |
-10:00:28.8 |
HIP 74908 |
21.02 |
| 2026-04-06 12:00 |
15:17:16.89 |
-09:59:30.8 |
HIP 74908 |
22.23 |
| 2026-04-07 00:00 |
15:17:07.78 |
-09:58:32.8 |
HIP 74908 |
23.63 |
| 2026-04-07 12:00 |
15:16:58.62 |
-09:57:34.8 |
HIP 74908 |
25.21 |
| 2026-04-08 00:00 |
15:16:49.42 |
-09:56:36.6 |
HIP 74647 |
25.92 |
| 2026-04-08 12:00 |
15:16:40.17 |
-09:55:38.4 |
HIP 74647 |
24.06 |
| 2026-04-09 00:00 |
15:16:30.86 |
-09:54:40.1 |
HIP 74647 |
22.30 |
| 2026-04-09 12:00 |
15:16:21.52 |
-09:53:41.8 |
HIP 74647 |
20.69 |
| 2026-04-10 00:00 |
15:16:12.12 |
-09:52:43.4 |
HIP 74647 |
19.26 |
| 2026-04-10 12:00 |
15:16:02.68 |
-09:51:45.0 |
HIP 74647 |
18.06 |
| 2026-04-11 00:00 |
15:15:53.20 |
-09:50:46.5 |
HIP 74647 |
17.14 |
| 2026-04-11 12:00 |
15:15:43.67 |
-09:49:47.9 |
HIP 74647 |
16.55 |
| 2026-04-12 00:00 |
15:15:34.09 |
-09:48:49.4 |
HIP 74647 |
16.34 |
| 2026-04-12 12:00 |
15:15:24.48 |
-09:47:50.8 |
HIP 74647 |
16.52 |
| 2026-04-13 00:00 |
15:15:14.82 |
-09:46:52.1 |
HIP 74647 |
17.09 |
| 2026-04-13 12:00 |
15:15:05.12 |
-09:45:53.5 |
HIP 74647 |
18.01 |
| 2026-04-14 00:00 |
15:14:55.39 |
-09:44:54.8 |
HIP 74647 |
19.24 |
| 2026-04-14 12:00 |
15:14:45.61 |
-09:43:56.1 |
HIP 74548 |
18.63 |
| 2026-04-15 00:00 |
15:14:35.79 |
-09:42:57.4 |
HIP 74548 |
16.37 |
| 2026-04-15 12:00 |
15:14:25.94 |
-09:41:58.7 |
HIP 74548 |
14.24 |
| 2026-04-16 00:00 |
15:14:16.05 |
-09:41:00.0 |
HIP 74548 |
12.29 |