메타데이터
| 항목 |
값 |
| Designation |
C/2020 F7 (Lemmon) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2021-11-14T02:39:42.822720Z |
| Orbit solution date (soln_date, UTC) |
2023-12-28T19:42:30Z |
| Obs used |
608 |
| NEO |
- |
| M1 |
6.600 |
| K1 |
10.750 |
| PC |
- |
Osculating 궤도요소
| 항목 |
값 |
| Epoch (epoch_cal, TDB) |
2020-12-09.0000000 |
| e |
0.99310004 |
| q (au) |
5.331815 |
| a (au) |
772.731657 |
| i (deg) |
93.951702 |
| Ω (om, deg) |
321.886317 |
| ω (w, deg) |
227.985641 |
| M (ma, deg) |
359.984394 |
밝기
산란 + 전체 선형
$$
M_a = (2.349 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
모델 상수
| 항목 |
값 |
| H0 |
2.349 |
| n |
6.000 |
| gf |
0.977 |
| gb |
-0.693 |
| k |
1.000 |
| 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 |
| 2020-01-04 |
2021-11-11 |
+4.9500 |
-3.771 |
| 2021-11-14 |
2023-12-20 |
-12.9005 |
+9.601 |
log10 r = log10(태양거리/AU), Δ = 지구거리(AU)
천체력
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
22:34:24.37 |
-46:03:54.8 |
HIP 111456 |
17.32 |
| 2026-09-20 12:00 |
22:34:10.57 |
-46:03:28.8 |
HIP 111456 |
17.63 |
| 2026-09-21 00:00 |
22:33:56.83 |
-46:03:01.9 |
HIP 111456 |
18.25 |
| 2026-09-21 12:00 |
22:33:43.14 |
-46:02:34.1 |
HIP 111456 |
19.14 |
| 2026-09-22 00:00 |
22:33:29.52 |
-46:02:05.4 |
HIP 111456 |
20.26 |
| 2026-09-22 12:00 |
22:33:15.96 |
-46:01:35.8 |
HIP 111456 |
21.58 |
| 2026-09-23 00:00 |
22:33:02.46 |
-46:01:05.3 |
HIP 111456 |
23.06 |
| 2026-09-23 12:00 |
22:32:49.02 |
-46:00:33.9 |
HIP 111456 |
24.67 |
| 2026-09-24 00:00 |
22:32:35.65 |
-46:00:01.7 |
HIP 111456 |
26.38 |
| 2026-09-24 12:00 |
22:32:22.35 |
-45:59:28.5 |
HIP 111052 |
26.60 |
| 2026-09-25 00:00 |
22:32:09.11 |
-45:58:54.5 |
HIP 111052 |
24.48 |
| 2026-09-25 12:00 |
22:31:55.94 |
-45:58:19.5 |
HIP 111052 |
22.41 |
| 2026-09-26 00:00 |
22:31:42.84 |
-45:57:43.7 |
HIP 111052 |
20.43 |
| 2026-09-26 12:00 |
22:31:29.81 |
-45:57:07.1 |
HIP 111052 |
18.54 |
| 2026-09-27 00:00 |
22:31:16.84 |
-45:56:29.5 |
HIP 111052 |
16.79 |
| 2026-09-27 12:00 |
22:31:03.95 |
-45:55:51.1 |
HIP 111052 |
15.22 |
| 2026-09-28 00:00 |
22:30:51.14 |
-45:55:11.8 |
HIP 111052 |
13.87 |
| 2026-09-28 12:00 |
22:30:38.39 |
-45:54:31.7 |
HIP 111052 |
12.83 |
| 2026-09-29 00:00 |
22:30:25.72 |
-45:53:50.7 |
HIP 111052 |
12.17 |
| 2026-09-29 12:00 |
22:30:13.13 |
-45:53:08.9 |
HIP 111052 |
11.93 |
| 2026-09-30 00:00 |
22:30:00.61 |
-45:52:26.2 |
HIP 111052 |
12.15 |
| 2026-09-30 12:00 |
22:29:48.16 |
-45:51:42.6 |
HIP 111052 |
12.79 |
| 2026-10-01 00:00 |
22:29:35.80 |
-45:50:58.2 |
HIP 111052 |
13.80 |
| 2026-10-01 12:00 |
22:29:23.52 |
-45:50:13.0 |
HIP 111052 |
15.10 |
| 2026-10-02 00:00 |
22:29:11.31 |
-45:49:26.9 |
HIP 110970 |
15.55 |
| 2026-10-02 12:00 |
22:28:59.19 |
-45:48:40.0 |
HIP 110970 |
14.64 |
| 2026-10-03 00:00 |
22:28:47.14 |
-45:47:52.3 |
HIP 110970 |
14.02 |
| 2026-10-03 12:00 |
22:28:35.18 |
-45:47:03.8 |
HIP 110970 |
13.73 |
| 2026-10-04 00:00 |
22:28:23.30 |
-45:46:14.4 |
HIP 110970 |
13.78 |
| 2026-10-04 12:00 |
22:28:11.51 |
-45:45:24.2 |
HIP 110970 |
14.16 |
| 2026-10-05 00:00 |
22:27:59.80 |
-45:44:33.2 |
HIP 110795 |
14.42 |
| 2026-10-05 12:00 |
22:27:48.18 |
-45:43:41.4 |
HIP 110795 |
12.24 |
| 2026-10-06 00:00 |
22:27:36.64 |
-45:42:48.7 |
HIP 110795 |
10.07 |
| 2026-10-06 12:00 |
22:27:25.20 |
-45:41:55.3 |
HIP 110795 |
7.93 |
| 2026-10-07 00:00 |
22:27:13.84 |
-45:41:01.1 |
HIP 110795 |
5.82 |
| 2026-10-07 12:00 |
22:27:02.57 |
-45:40:06.0 |
HIP 110795 |
3.79 |
| 2026-10-08 00:00 |
22:26:51.39 |
-45:39:10.2 |
HIP 110795 |
2.07 |
| 2026-10-08 12:00 |
22:26:40.30 |
-45:38:13.6 |
HIP 110795 |
1.87 |
| 2026-10-09 00:00 |
22:26:29.30 |
-45:37:16.2 |
HIP 110795 |
3.45 |
| 2026-10-09 12:00 |
22:26:18.40 |
-45:36:18.1 |
HIP 110795 |
5.42 |
| 2026-10-10 00:00 |
22:26:07.59 |
-45:35:19.1 |
HIP 110795 |
7.47 |
| 2026-10-10 12:00 |
22:25:56.87 |
-45:34:19.5 |
HIP 110795 |
9.55 |
| 2026-10-11 00:00 |
22:25:46.25 |
-45:33:19.0 |
HIP 110795 |
11.63 |