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 |
0.970 |
| gb |
-0.676 |
| k |
1.000 |
| δ90 |
9.976 |
| 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) |
| 2026-03-26 00:00 |
23:02:20.42 |
-43:02:02.7 |
HIP 113760 |
3.86 |
| 2026-03-26 12:00 |
23:02:29.53 |
-43:01:21.1 |
HIP 113760 |
3.93 |
| 2026-03-27 00:00 |
23:02:38.61 |
-43:00:40.3 |
HIP 113760 |
4.75 |
| 2026-03-27 12:00 |
23:02:47.64 |
-43:00:00.2 |
HIP 113760 |
6.01 |
| 2026-03-28 00:00 |
23:02:56.63 |
-42:59:20.9 |
HIP 113760 |
7.48 |
| 2026-03-28 12:00 |
23:03:05.59 |
-42:58:42.4 |
HIP 113858 |
7.31 |
| 2026-03-29 00:00 |
23:03:14.50 |
-42:58:04.6 |
HIP 113858 |
7.09 |
| 2026-03-29 12:00 |
23:03:23.37 |
-42:57:27.6 |
HIP 113858 |
7.29 |
| 2026-03-30 00:00 |
23:03:32.20 |
-42:56:51.4 |
HIP 113858 |
7.86 |
| 2026-03-30 12:00 |
23:03:40.99 |
-42:56:16.0 |
HIP 113858 |
8.73 |
| 2026-03-31 00:00 |
23:03:49.73 |
-42:55:41.3 |
HIP 113858 |
9.80 |
| 2026-03-31 12:00 |
23:03:58.43 |
-42:55:07.4 |
HIP 113858 |
11.02 |
| 2026-04-01 00:00 |
23:04:07.09 |
-42:54:34.2 |
HIP 113858 |
12.33 |
| 2026-04-01 12:00 |
23:04:15.70 |
-42:54:01.8 |
HIP 113858 |
13.71 |
| 2026-04-02 00:00 |
23:04:24.26 |
-42:53:30.2 |
HIP 113858 |
15.13 |
| 2026-04-02 12:00 |
23:04:32.79 |
-42:52:59.4 |
HIP 113858 |
16.58 |
| 2026-04-03 00:00 |
23:04:41.26 |
-42:52:29.3 |
HIP 113858 |
18.05 |
| 2026-04-03 12:00 |
23:04:49.69 |
-42:52:00.0 |
HIP 113858 |
19.53 |
| 2026-04-04 00:00 |
23:04:58.07 |
-42:51:31.4 |
HIP 113858 |
21.01 |
| 2026-04-04 12:00 |
23:05:06.40 |
-42:51:03.7 |
HIP 114067 |
21.72 |
| 2026-04-05 00:00 |
23:05:14.68 |
-42:50:36.7 |
HIP 114067 |
20.58 |
| 2026-04-05 12:00 |
23:05:22.92 |
-42:50:10.5 |
HIP 114067 |
19.51 |
| 2026-04-06 00:00 |
23:05:31.10 |
-42:49:45.0 |
HIP 114067 |
18.54 |
| 2026-04-06 12:00 |
23:05:39.24 |
-42:49:20.4 |
HIP 114067 |
17.66 |
| 2026-04-07 00:00 |
23:05:47.32 |
-42:48:56.5 |
HIP 114067 |
16.90 |
| 2026-04-07 12:00 |
23:05:55.35 |
-42:48:33.3 |
HIP 114067 |
16.26 |
| 2026-04-08 00:00 |
23:06:03.33 |
-42:48:11.0 |
HIP 114067 |
15.76 |
| 2026-04-08 12:00 |
23:06:11.26 |
-42:47:49.4 |
HIP 114067 |
15.40 |
| 2026-04-09 00:00 |
23:06:19.14 |
-42:47:28.6 |
HIP 114067 |
15.19 |
| 2026-04-09 12:00 |
23:06:26.96 |
-42:47:08.6 |
HIP 114067 |
15.14 |
| 2026-04-10 00:00 |
23:06:34.72 |
-42:46:49.4 |
HIP 114067 |
15.24 |
| 2026-04-10 12:00 |
23:06:42.44 |
-42:46:30.9 |
HIP 114067 |
15.49 |
| 2026-04-11 00:00 |
23:06:50.09 |
-42:46:13.2 |
HIP 114067 |
15.87 |
| 2026-04-11 12:00 |
23:06:57.69 |
-42:45:56.3 |
HIP 114067 |
16.38 |
| 2026-04-12 00:00 |
23:07:05.24 |
-42:45:40.2 |
HIP 114067 |
16.99 |
| 2026-04-12 12:00 |
23:07:12.72 |
-42:45:24.9 |
HIP 114067 |
17.70 |
| 2026-04-13 00:00 |
23:07:20.15 |
-42:45:10.3 |
HIP 114067 |
18.49 |
| 2026-04-13 12:00 |
23:07:27.52 |
-42:44:56.5 |
HIP 114067 |
19.35 |
| 2026-04-14 00:00 |
23:07:34.83 |
-42:44:43.5 |
HIP 114303 |
19.72 |
| 2026-04-14 12:00 |
23:07:42.08 |
-42:44:31.3 |
HIP 114303 |
18.58 |
| 2026-04-15 00:00 |
23:07:49.27 |
-42:44:19.8 |
HIP 114303 |
17.49 |
| 2026-04-15 12:00 |
23:07:56.40 |
-42:44:09.2 |
HIP 114303 |
16.45 |
| 2026-04-16 00:00 |
23:08:03.47 |
-42:43:59.3 |
HIP 114303 |
15.47 |