메타데이터
| 항목 |
값 |
| Designation |
C/2020 O2 (Amaral) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2021-08-28T14:45:24.552000Z |
| Orbit solution date (soln_date, UTC) |
2024-05-14T12:42:17Z |
| Obs used |
1595 |
| NEO |
- |
| M1 |
5.900 |
| K1 |
10.500 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2020-07-23T23:20:29.184000Z |
| Discovery magnitude (MPC) |
18.10 R |
| Discovery observatory (MPC) |
X74 · Observatório Campo dos Amarais |
Osculating 궤도요소
| 항목 |
값 |
| Epoch (epoch_cal, TDB) |
2022-02-27.0000000 |
| e |
1.00232543 |
| q (au) |
4.862254 |
| a (au) |
-2090.901073 |
| i (deg) |
71.750811 |
| Ω (om, deg) |
256.757254 |
| ω (w, deg) |
10.309432 |
| M (ma, deg) |
0.001880 |
밝기
산란 + 전체 선형
$$
M_a = (4.977 + 4.155\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
모델 상수
| 항목 |
값 |
| H0 |
4.977 |
| n |
4.155 |
| gf |
1.000 |
| gb |
-0.948 |
| 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 |
| 2020-07-23 |
2021-08-28 |
+6.9479 |
-4.707 |
| 2021-08-29 |
2023-09-21 |
-0.9103 |
+0.615 |
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 |
23:59:16.39 |
+72:08:39.5 |
HIP 123 |
12.03 |
| 2026-09-20 12:00 |
23:58:56.26 |
+72:08:22.0 |
HIP 118037 |
11.34 |
| 2026-09-21 00:00 |
23:58:36.13 |
+72:08:03.4 |
HIP 118037 |
9.77 |
| 2026-09-21 12:00 |
23:58:16.00 |
+72:07:43.5 |
HIP 118037 |
8.19 |
| 2026-09-22 00:00 |
23:57:55.88 |
+72:07:22.3 |
HIP 118037 |
6.62 |
| 2026-09-22 12:00 |
23:57:35.77 |
+72:07:00.0 |
HIP 118037 |
5.04 |
| 2026-09-23 00:00 |
23:57:15.67 |
+72:06:36.3 |
HIP 118037 |
3.46 |
| 2026-09-23 12:00 |
23:56:55.58 |
+72:06:11.5 |
HIP 118037 |
1.89 |
| 2026-09-24 00:00 |
23:56:35.52 |
+72:05:45.4 |
HIP 118037 |
0.52 |
| 2026-09-24 12:00 |
23:56:15.47 |
+72:05:18.2 |
HIP 118037 |
1.45 |
| 2026-09-25 00:00 |
23:55:55.45 |
+72:04:49.6 |
HIP 118037 |
3.02 |
| 2026-09-25 12:00 |
23:55:35.46 |
+72:04:19.9 |
HIP 118037 |
4.62 |
| 2026-09-26 00:00 |
23:55:15.50 |
+72:03:48.9 |
HIP 118037 |
6.23 |
| 2026-09-26 12:00 |
23:54:55.57 |
+72:03:16.8 |
HIP 118037 |
7.85 |
| 2026-09-27 00:00 |
23:54:35.67 |
+72:02:43.4 |
HIP 118037 |
9.47 |
| 2026-09-27 12:00 |
23:54:15.82 |
+72:02:08.7 |
HIP 118037 |
11.11 |
| 2026-09-28 00:00 |
23:53:56.01 |
+72:01:32.9 |
HIP 118037 |
12.74 |
| 2026-09-28 12:00 |
23:53:36.24 |
+72:00:55.9 |
HIP 118037 |
14.38 |
| 2026-09-29 00:00 |
23:53:16.52 |
+72:00:17.6 |
HIP 118037 |
16.03 |
| 2026-09-29 12:00 |
23:52:56.85 |
+71:59:38.2 |
HIP 118037 |
17.68 |
| 2026-09-30 00:00 |
23:52:37.24 |
+71:58:57.5 |
HIP 118037 |
19.33 |
| 2026-09-30 12:00 |
23:52:17.68 |
+71:58:15.7 |
HIP 118037 |
20.99 |
| 2026-10-01 00:00 |
23:51:58.18 |
+71:57:32.6 |
HIP 118037 |
22.66 |
| 2026-10-01 12:00 |
23:51:38.74 |
+71:56:48.4 |
HIP 118037 |
24.32 |
| 2026-10-02 00:00 |
23:51:19.37 |
+71:56:03.0 |
HIP 118037 |
26.00 |
| 2026-10-02 12:00 |
23:51:00.07 |
+71:55:16.3 |
HIP 118037 |
27.68 |
| 2026-10-03 00:00 |
23:50:40.84 |
+71:54:28.5 |
HIP 117355 |
28.39 |
| 2026-10-03 12:00 |
23:50:21.68 |
+71:53:39.5 |
HIP 117355 |
26.95 |
| 2026-10-04 00:00 |
23:50:02.60 |
+71:52:49.4 |
HIP 117355 |
25.54 |
| 2026-10-04 12:00 |
23:49:43.60 |
+71:51:58.0 |
HIP 117355 |
24.14 |
| 2026-10-05 00:00 |
23:49:24.68 |
+71:51:05.5 |
HIP 117355 |
22.78 |
| 2026-10-05 12:00 |
23:49:05.84 |
+71:50:11.8 |
HIP 117355 |
21.45 |
| 2026-10-06 00:00 |
23:48:47.10 |
+71:49:16.9 |
HIP 117355 |
20.16 |
| 2026-10-06 12:00 |
23:48:28.44 |
+71:48:20.9 |
HIP 117355 |
18.93 |
| 2026-10-07 00:00 |
23:48:09.88 |
+71:47:23.8 |
HIP 117355 |
17.76 |
| 2026-10-07 12:00 |
23:47:51.42 |
+71:46:25.5 |
HIP 117355 |
16.67 |
| 2026-10-08 00:00 |
23:47:33.06 |
+71:45:26.0 |
HIP 117355 |
15.68 |
| 2026-10-08 12:00 |
23:47:14.79 |
+71:44:25.4 |
HIP 117355 |
14.82 |
| 2026-10-09 00:00 |
23:46:56.64 |
+71:43:23.7 |
HIP 117355 |
14.10 |
| 2026-10-09 12:00 |
23:46:38.59 |
+71:42:20.9 |
HIP 117355 |
13.56 |
| 2026-10-10 00:00 |
23:46:20.65 |
+71:41:16.9 |
HIP 117355 |
13.21 |
| 2026-10-10 12:00 |
23:46:02.83 |
+71:40:11.8 |
HIP 117355 |
13.08 |
| 2026-10-11 00:00 |
23:45:45.12 |
+71:39:05.6 |
HIP 117355 |
13.17 |