메타데이터
| 항목 |
값 |
| Designation |
C/2018 U1 (Lemmon) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2021-11-02T19:19:13.019520Z |
| Orbit solution date (soln_date, UTC) |
2025-04-11T14:44:11Z |
| Obs used |
2459 |
| NEO |
- |
| M1 |
6.400 |
| K1 |
8.750 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2018-10-27T04:27:14.112000Z |
| Discovery magnitude (MPC) |
20.00 G |
| Discovery observatory (MPC) |
G96 · Mt. Lemmon Survey |
Osculating 궤도요소
| 항목 |
값 |
| Epoch (epoch_cal, TDB) |
2020-09-11.0000000 |
| e |
1.00080698 |
| q (au) |
4.993873 |
| a (au) |
-6188.361643 |
| i (deg) |
108.301379 |
| Ω (om, deg) |
75.476939 |
| ω (w, deg) |
180.420486 |
| M (ma, deg) |
-0.000846 |
밝기
산란 + 전체 선형
$$
M_a = (5.982 + 3.665\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
모델 상수
| 항목 |
값 |
| H0 |
5.982 |
| n |
3.665 |
| gf |
0.858 |
| gb |
-0.500 |
| k |
0.942 |
| δ90 |
2.042 |
| 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 |
| 2018-10-27 |
2019-05-30 |
+10.1321 |
-9.496 |
| 2019-05-30 |
2021-10-08 |
-0.4295 |
+0.235 |
| 2022-02-03 |
2023-06-21 |
+3.8998 |
-2.549 |
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 |
07:03:19.34 |
-50:03:09.3 |
HIP 33928 |
8.71 |
| 2026-03-26 12:00 |
07:03:14.92 |
-50:00:13.4 |
HIP 33957 |
6.53 |
| 2026-03-27 00:00 |
07:03:10.65 |
-49:57:17.6 |
HIP 33957 |
4.32 |
| 2026-03-27 12:00 |
07:03:06.52 |
-49:54:21.7 |
HIP 33957 |
3.59 |
| 2026-03-28 00:00 |
07:03:02.53 |
-49:51:25.9 |
HIP 33957 |
5.04 |
| 2026-03-28 12:00 |
07:02:58.69 |
-49:48:30.0 |
HIP 33957 |
7.48 |
| 2026-03-29 00:00 |
07:02:54.99 |
-49:45:34.3 |
HIP 33957 |
10.22 |
| 2026-03-29 12:00 |
07:02:51.43 |
-49:42:38.6 |
HIP 34059 |
12.61 |
| 2026-03-30 00:00 |
07:02:48.00 |
-49:39:42.9 |
HIP 34059 |
11.61 |
| 2026-03-30 12:00 |
07:02:44.72 |
-49:36:47.3 |
HIP 34059 |
11.30 |
| 2026-03-31 00:00 |
07:02:41.58 |
-49:33:51.9 |
HIP 34059 |
11.74 |
| 2026-03-31 12:00 |
07:02:38.58 |
-49:30:56.5 |
HIP 34059 |
12.85 |
| 2026-04-01 00:00 |
07:02:35.72 |
-49:28:01.2 |
HIP 34059 |
14.47 |
| 2026-04-01 12:00 |
07:02:32.99 |
-49:25:06.1 |
HIP 34059 |
16.45 |
| 2026-04-02 00:00 |
07:02:30.40 |
-49:22:11.0 |
HIP 34059 |
18.67 |
| 2026-04-02 12:00 |
07:02:27.95 |
-49:19:16.2 |
HIP 33900 |
19.86 |
| 2026-04-03 00:00 |
07:02:25.63 |
-49:16:21.5 |
HIP 33900 |
16.92 |
| 2026-04-03 12:00 |
07:02:23.45 |
-49:13:26.9 |
HIP 33900 |
13.99 |
| 2026-04-04 00:00 |
07:02:21.41 |
-49:10:32.5 |
HIP 33900 |
11.07 |
| 2026-04-04 12:00 |
07:02:19.50 |
-49:07:38.3 |
HIP 33900 |
8.16 |
| 2026-04-05 00:00 |
07:02:17.72 |
-49:04:44.3 |
HIP 33900 |
5.26 |
| 2026-04-05 12:00 |
07:02:16.07 |
-49:01:50.5 |
HIP 33900 |
2.42 |
| 2026-04-06 00:00 |
07:02:14.56 |
-48:58:57.0 |
HIP 33900 |
1.01 |
| 2026-04-06 12:00 |
07:02:13.18 |
-48:56:03.6 |
HIP 33900 |
3.61 |
| 2026-04-07 00:00 |
07:02:11.93 |
-48:53:10.5 |
HIP 33900 |
6.46 |
| 2026-04-07 12:00 |
07:02:10.82 |
-48:50:17.6 |
HIP 33900 |
9.34 |
| 2026-04-08 00:00 |
07:02:09.83 |
-48:47:25.0 |
HIP 33900 |
12.21 |
| 2026-04-08 12:00 |
07:02:08.97 |
-48:44:32.7 |
HIP 33900 |
15.09 |
| 2026-04-09 00:00 |
07:02:08.25 |
-48:41:40.7 |
HIP 33732 |
17.02 |
| 2026-04-09 12:00 |
07:02:07.65 |
-48:38:48.9 |
HIP 33732 |
17.52 |
| 2026-04-10 00:00 |
07:02:07.17 |
-48:35:57.4 |
HIP 33732 |
18.48 |
| 2026-04-10 12:00 |
07:02:06.83 |
-48:33:06.3 |
HIP 33732 |
19.82 |
| 2026-04-11 00:00 |
07:02:06.61 |
-48:30:15.5 |
HIP 33732 |
21.47 |
| 2026-04-11 12:00 |
07:02:06.52 |
-48:27:25.0 |
HIP 33899 |
21.89 |
| 2026-04-12 00:00 |
07:02:06.55 |
-48:24:34.8 |
HIP 33899 |
19.05 |
| 2026-04-12 12:00 |
07:02:06.71 |
-48:21:45.0 |
HIP 33899 |
16.22 |
| 2026-04-13 00:00 |
07:02:07.00 |
-48:18:55.5 |
HIP 33899 |
13.40 |
| 2026-04-13 12:00 |
07:02:07.40 |
-48:16:06.5 |
HIP 33899 |
10.58 |
| 2026-04-14 00:00 |
07:02:07.93 |
-48:13:17.8 |
HIP 33899 |
7.77 |
| 2026-04-14 12:00 |
07:02:08.58 |
-48:10:29.5 |
HIP 33899 |
4.96 |
| 2026-04-15 00:00 |
07:02:09.36 |
-48:07:41.6 |
HIP 33899 |
2.16 |
| 2026-04-15 12:00 |
07:02:10.25 |
-48:04:54.1 |
HIP 33899 |
0.64 |
| 2026-04-16 00:00 |
07:02:11.27 |
-48:02:07.0 |
HIP 33899 |
3.43 |