C/2021 A1 (Leonard)
메타데이터
| 항목 | 값 |
|---|---|
| Designation | C/2021 A1 (Leonard) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2022-01-03T07:01:27.517440Z |
| Orbit solution date (soln_date, UTC) | 2025-01-02T20:12:26Z |
| Obs used | 2422 |
| NEO | - |
| M1 | 12.500 |
| K1 | 4.500 |
| PC | - |
| Discovery observation (MPC, UTC) | 2021-01-03T13:00:51.696000Z |
| Discovery magnitude (MPC) | 19.00 G |
| Discovery observatory (MPC) | G96 · Mt. Lemmon Survey |
Osculating 궤도요소
| 항목 | 값 |
|---|---|
| Epoch (epoch_cal, TDB) | 2021-07-11.0000000 |
| e | 1.00010048 |
| q (au) | 0.615230 |
| a (au) | -6122.881779 |
| i (deg) | 132.685813 |
| Ω (om, deg) | 255.889104 |
| ω (w, deg) | 225.087713 |
| M (ma, deg) | -0.000363 |
밝기
산란 + 전체 선형
$$ M_a = (11.021 + 5.164\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
모델 상수
| 항목 | 값 |
|---|---|
| H0 | 11.021 |
| n | 5.164 |
| gf | 0.800 |
| gb | -0.920 |
| k | 0.834 |
| δ90 | 10.000 |
| 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
잔차 (구간 선형)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| 시작일 (UTC) | 끝 (UTC) | a | b |
|---|---|---|---|
| 2020-04-11 | 2021-10-30 | +1.5118 | -0.912 |
| 2021-10-30 | 2021-12-06 | -9.8457 | +0.200 |
| 2021-12-06 | 2022-01-03 | +28.4756 | +3.588 |
| 2022-01-03 | 2022-05-28 | +0.7618 | -1.274 |
log10 r = log10(태양거리/AU), Δ = 지구거리(AU)
천체력
| Date/Time (UTC) | RA (J2000) | Dec (J2000) | Nearest HIP | Dist from HIP (arcmin) |
|---|---|---|---|---|
| 2026-03-26 00:00 | 16:23:19.75 | -05:30:39.6 | HIP 80191 | 18.55 |
| 2026-03-26 12:00 | 16:23:15.28 | -05:29:49.4 | HIP 80191 | 18.11 |
| 2026-03-27 00:00 | 16:23:10.74 | -05:28:59.2 | HIP 80191 | 17.77 |
| 2026-03-27 12:00 | 16:23:06.14 | -05:28:09.0 | HIP 80191 | 17.51 |
| 2026-03-28 00:00 | 16:23:01.46 | -05:27:18.7 | HIP 80191 | 17.36 |
| 2026-03-28 12:00 | 16:22:56.72 | -05:26:28.5 | HIP 80191 | 17.32 |
| 2026-03-29 00:00 | 16:22:51.91 | -05:25:38.1 | HIP 80191 | 17.39 |
| 2026-03-29 12:00 | 16:22:47.04 | -05:24:47.8 | HIP 80191 | 17.58 |
| 2026-03-30 00:00 | 16:22:42.10 | -05:23:57.4 | HIP 80191 | 17.88 |
| 2026-03-30 12:00 | 16:22:37.09 | -05:23:07.1 | HIP 80191 | 18.29 |
| 2026-03-31 00:00 | 16:22:32.02 | -05:22:16.7 | HIP 80191 | 18.81 |
| 2026-03-31 12:00 | 16:22:26.89 | -05:21:26.3 | HIP 80191 | 19.43 |
| 2026-04-01 00:00 | 16:22:21.68 | -05:20:35.8 | HIP 80191 | 20.15 |
| 2026-04-01 12:00 | 16:22:16.42 | -05:19:45.4 | HIP 80191 | 20.96 |
| 2026-04-02 00:00 | 16:22:11.09 | -05:18:55.0 | HIP 80191 | 21.85 |
| 2026-04-02 12:00 | 16:22:05.70 | -05:18:04.6 | HIP 80191 | 22.82 |
| 2026-04-03 00:00 | 16:22:00.24 | -05:17:14.2 | HIP 80191 | 23.86 |
| 2026-04-03 12:00 | 16:21:54.72 | -05:16:23.8 | HIP 80191 | 24.95 |
| 2026-04-04 00:00 | 16:21:49.14 | -05:15:33.4 | HIP 80191 | 26.11 |
| 2026-04-04 12:00 | 16:21:43.49 | -05:14:43.0 | HIP 80191 | 27.32 |
| 2026-04-05 00:00 | 16:21:37.79 | -05:13:52.7 | HIP 80191 | 28.57 |
| 2026-04-05 12:00 | 16:21:32.02 | -05:13:02.4 | HIP 80191 | 29.87 |
| 2026-04-06 00:00 | 16:21:26.19 | -05:12:12.0 | HIP 80191 | 31.21 |
| 2026-04-06 12:00 | 16:21:20.30 | -05:11:21.8 | HIP 80191 | 32.58 |
| 2026-04-07 00:00 | 16:21:14.35 | -05:10:31.5 | HIP 80191 | 33.99 |
| 2026-04-07 12:00 | 16:21:08.35 | -05:09:41.3 | HIP 80191 | 35.44 |
| 2026-04-08 00:00 | 16:21:02.28 | -05:08:51.1 | HIP 80191 | 36.91 |
| 2026-04-08 12:00 | 16:20:56.15 | -05:08:01.0 | HIP 80037 | 35.97 |
| 2026-04-09 00:00 | 16:20:49.97 | -05:07:10.9 | HIP 80037 | 34.76 |
| 2026-04-09 12:00 | 16:20:43.72 | -05:06:20.9 | HIP 80037 | 33.60 |
| 2026-04-10 00:00 | 16:20:37.42 | -05:05:30.9 | HIP 80037 | 32.49 |
| 2026-04-10 12:00 | 16:20:31.06 | -05:04:41.0 | HIP 80037 | 31.44 |
| 2026-04-11 00:00 | 16:20:24.65 | -05:03:51.2 | HIP 80037 | 30.46 |
| 2026-04-11 12:00 | 16:20:18.18 | -05:03:01.4 | HIP 80037 | 29.56 |
| 2026-04-12 00:00 | 16:20:11.65 | -05:02:11.6 | HIP 80037 | 28.74 |
| 2026-04-12 12:00 | 16:20:05.07 | -05:01:22.0 | HIP 80037 | 28.02 |
| 2026-04-13 00:00 | 16:19:58.43 | -05:00:32.4 | HIP 80037 | 27.41 |
| 2026-04-13 12:00 | 16:19:51.74 | -04:59:42.9 | HIP 80037 | 26.92 |
| 2026-04-14 00:00 | 16:19:44.99 | -04:58:53.5 | HIP 80037 | 26.56 |
| 2026-04-14 12:00 | 16:19:38.20 | -04:58:04.1 | HIP 79882 | 25.68 |
| 2026-04-15 00:00 | 16:19:31.34 | -04:57:14.9 | HIP 79882 | 23.85 |
| 2026-04-15 12:00 | 16:19:24.44 | -04:56:25.8 | HIP 79882 | 22.02 |
| 2026-04-16 00:00 | 16:19:17.49 | -04:55:36.7 | HIP 79882 | 20.20 |