메타데이터
| 항목 |
값 |
| Designation |
C/2019 S4 (Lemmon) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2020-04-07T22:29:16.782720Z |
| Orbit solution date (soln_date, UTC) |
2021-09-20T00:12:43Z |
| Obs used |
267 |
| NEO |
- |
| M1 |
8.600 |
| K1 |
13.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2019-09-17T10:53:32.640000Z |
| Discovery magnitude (MPC) |
20.30 G |
| Discovery observatory (MPC) |
G96 · University of Arizona Mt. Lemmon Survey |
Osculating 궤도요소
| 항목 |
값 |
| Epoch (epoch_cal, TDB) |
2020-02-18.0000000 |
| e |
0.98581834 |
| q (au) |
3.441733 |
| a (au) |
242.688906 |
| i (deg) |
92.025259 |
| Ω (om, deg) |
63.169569 |
| ω (w, deg) |
71.354510 |
| M (ma, deg) |
359.986982 |
밝기
산란 + 전체 선형
$$
M_a = (6.827 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
모델 상수
| 항목 |
값 |
| H0 |
6.827 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| 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 |
| 2019-09-17 |
2020-04-01 |
+21.5169 |
-10.890 |
| 2020-05-29 |
2020-10-30 |
-14.1476 |
+7.524 |
| 2020-10-30 |
2021-09-12 |
+6.0879 |
-4.406 |
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 |
15:29:25.08 |
-36:56:58.5 |
HIP 75647 |
27.64 |
| 2026-09-20 12:00 |
15:29:29.40 |
-36:57:01.1 |
HIP 75647 |
28.45 |
| 2026-09-21 00:00 |
15:29:33.77 |
-36:57:04.1 |
HIP 75922 |
28.08 |
| 2026-09-21 12:00 |
15:29:38.20 |
-36:57:07.3 |
HIP 75922 |
27.72 |
| 2026-09-22 00:00 |
15:29:42.68 |
-36:57:10.8 |
HIP 75922 |
27.38 |
| 2026-09-22 12:00 |
15:29:47.22 |
-36:57:14.7 |
HIP 75922 |
27.05 |
| 2026-09-23 00:00 |
15:29:51.81 |
-36:57:18.9 |
HIP 75922 |
26.74 |
| 2026-09-23 12:00 |
15:29:56.46 |
-36:57:23.3 |
HIP 75922 |
26.46 |
| 2026-09-24 00:00 |
15:30:01.16 |
-36:57:28.1 |
HIP 75922 |
26.19 |
| 2026-09-24 12:00 |
15:30:05.91 |
-36:57:33.2 |
HIP 75922 |
25.95 |
| 2026-09-25 00:00 |
15:30:10.71 |
-36:57:38.6 |
HIP 75922 |
25.74 |
| 2026-09-25 12:00 |
15:30:15.57 |
-36:57:44.3 |
HIP 75922 |
25.56 |
| 2026-09-26 00:00 |
15:30:20.48 |
-36:57:50.3 |
HIP 75922 |
25.40 |
| 2026-09-26 12:00 |
15:30:25.44 |
-36:57:56.6 |
HIP 75922 |
25.28 |
| 2026-09-27 00:00 |
15:30:30.45 |
-36:58:03.2 |
HIP 75922 |
25.19 |
| 2026-09-27 12:00 |
15:30:35.51 |
-36:58:10.2 |
HIP 75922 |
25.14 |
| 2026-09-28 00:00 |
15:30:40.62 |
-36:58:17.4 |
HIP 75975 |
24.89 |
| 2026-09-28 12:00 |
15:30:45.78 |
-36:58:25.0 |
HIP 75975 |
24.66 |
| 2026-09-29 00:00 |
15:30:50.99 |
-36:58:32.8 |
HIP 75975 |
24.46 |
| 2026-09-29 12:00 |
15:30:56.25 |
-36:58:41.0 |
HIP 75975 |
24.31 |
| 2026-09-30 00:00 |
15:31:01.56 |
-36:58:49.5 |
HIP 75975 |
24.19 |
| 2026-09-30 12:00 |
15:31:06.92 |
-36:58:58.3 |
HIP 75975 |
24.12 |
| 2026-10-01 00:00 |
15:31:12.32 |
-36:59:07.3 |
HIP 75975 |
24.09 |
| 2026-10-01 12:00 |
15:31:17.78 |
-36:59:16.7 |
HIP 75975 |
24.11 |
| 2026-10-02 00:00 |
15:31:23.28 |
-36:59:26.5 |
HIP 75975 |
24.17 |
| 2026-10-02 12:00 |
15:31:28.83 |
-36:59:36.5 |
HIP 75975 |
24.28 |
| 2026-10-03 00:00 |
15:31:34.42 |
-36:59:46.8 |
HIP 75975 |
24.44 |
| 2026-10-03 12:00 |
15:31:40.06 |
-36:59:57.4 |
HIP 75975 |
24.65 |
| 2026-10-04 00:00 |
15:31:45.75 |
-37:00:08.3 |
HIP 75975 |
24.91 |
| 2026-10-04 12:00 |
15:31:51.49 |
-37:00:19.6 |
HIP 75975 |
25.22 |
| 2026-10-05 00:00 |
15:31:57.26 |
-37:00:31.1 |
HIP 75975 |
25.58 |
| 2026-10-05 12:00 |
15:32:03.09 |
-37:00:43.0 |
HIP 75975 |
25.98 |
| 2026-10-06 00:00 |
15:32:08.95 |
-37:00:55.2 |
HIP 75975 |
26.43 |
| 2026-10-06 12:00 |
15:32:14.87 |
-37:01:07.6 |
HIP 75975 |
26.93 |
| 2026-10-07 00:00 |
15:32:20.82 |
-37:01:20.4 |
HIP 75975 |
27.47 |
| 2026-10-07 12:00 |
15:32:26.82 |
-37:01:33.5 |
HIP 75975 |
28.05 |
| 2026-10-08 00:00 |
15:32:32.86 |
-37:01:46.9 |
HIP 75975 |
28.68 |
| 2026-10-08 12:00 |
15:32:38.94 |
-37:02:00.6 |
HIP 75975 |
29.34 |
| 2026-10-09 00:00 |
15:32:45.07 |
-37:02:14.6 |
HIP 75975 |
30.04 |
| 2026-10-09 12:00 |
15:32:51.24 |
-37:02:28.9 |
HIP 75975 |
30.78 |
| 2026-10-10 00:00 |
15:32:57.44 |
-37:02:43.5 |
HIP 75975 |
31.56 |
| 2026-10-10 12:00 |
15:33:03.69 |
-37:02:58.4 |
HIP 75975 |
32.37 |
| 2026-10-11 00:00 |
15:33:09.98 |
-37:03:13.6 |
HIP 75975 |
33.21 |