메타데이터
| 항목 |
값 |
| Designation |
C/2020 U3 (Rankin) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2021-02-05T23:23:23.781120Z |
| Orbit solution date (soln_date, UTC) |
2023-04-24T19:06:41Z |
| Obs used |
178 |
| NEO |
- |
| M1 |
9.700 |
| K1 |
22.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2020-10-22T03:37:43.852800Z |
| Discovery magnitude (MPC) |
20.14 G |
| Discovery observatory (MPC) |
G96 · University of Arizona Mt. Lemmon Survey |
Osculating 궤도요소
| 항목 |
값 |
| Epoch (epoch_cal, TDB) |
2020-11-22.0000000 |
| e |
0.96479330 |
| q (au) |
2.276177 |
| a (au) |
64.651799 |
| i (deg) |
30.176991 |
| Ω (om, deg) |
282.679092 |
| ω (w, deg) |
124.262013 |
| M (ma, deg) |
359.855954 |
밝기
산란 + 전체 선형
$$
M_a = (11.589 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
모델 상수
| 항목 |
값 |
| H0 |
11.589 |
| 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 |
| 2020-07-21 |
2021-02-05 |
+3.5360 |
-1.291 |
| 2021-02-07 |
2021-10-31 |
+2.0235 |
-1.913 |
log10 r = log10(태양거리/AU), Δ = 지구거리(AU)
천체력
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
10:58:01.64 |
-26:33:11.4 |
HIP 53712 |
22.51 |
| 2026-06-01 12:00 |
10:58:02.44 |
-26:32:13.6 |
HIP 53712 |
22.93 |
| 2026-06-02 00:00 |
10:58:03.31 |
-26:31:16.2 |
HIP 53712 |
23.38 |
| 2026-06-02 12:00 |
10:58:04.24 |
-26:30:19.2 |
HIP 53712 |
23.83 |
| 2026-06-03 00:00 |
10:58:05.25 |
-26:29:22.6 |
HIP 53658 |
24.01 |
| 2026-06-03 12:00 |
10:58:06.32 |
-26:28:26.4 |
HIP 53658 |
23.05 |
| 2026-06-04 00:00 |
10:58:07.46 |
-26:27:30.6 |
HIP 53658 |
22.08 |
| 2026-06-04 12:00 |
10:58:08.67 |
-26:26:35.2 |
HIP 53658 |
21.12 |
| 2026-06-05 00:00 |
10:58:09.95 |
-26:25:40.2 |
HIP 53658 |
20.16 |
| 2026-06-05 12:00 |
10:58:11.30 |
-26:24:45.5 |
HIP 53658 |
19.21 |
| 2026-06-06 00:00 |
10:58:12.71 |
-26:23:51.3 |
HIP 53658 |
18.25 |
| 2026-06-06 12:00 |
10:58:14.20 |
-26:22:57.6 |
HIP 53658 |
17.29 |
| 2026-06-07 00:00 |
10:58:15.75 |
-26:22:04.2 |
HIP 53658 |
16.34 |
| 2026-06-07 12:00 |
10:58:17.36 |
-26:21:11.2 |
HIP 53658 |
15.38 |
| 2026-06-08 00:00 |
10:58:19.05 |
-26:20:18.7 |
HIP 53658 |
14.43 |
| 2026-06-08 12:00 |
10:58:20.80 |
-26:19:26.6 |
HIP 53658 |
13.48 |
| 2026-06-09 00:00 |
10:58:22.62 |
-26:18:34.9 |
HIP 53658 |
12.54 |
| 2026-06-09 12:00 |
10:58:24.50 |
-26:17:43.7 |
HIP 53658 |
11.59 |
| 2026-06-10 00:00 |
10:58:26.45 |
-26:16:52.9 |
HIP 53658 |
10.66 |
| 2026-06-10 12:00 |
10:58:28.47 |
-26:16:02.6 |
HIP 53658 |
9.72 |
| 2026-06-11 00:00 |
10:58:30.56 |
-26:15:12.7 |
HIP 53658 |
8.80 |
| 2026-06-11 12:00 |
10:58:32.71 |
-26:14:23.2 |
HIP 53658 |
7.88 |
| 2026-06-12 00:00 |
10:58:34.92 |
-26:13:34.2 |
HIP 53658 |
6.98 |
| 2026-06-12 12:00 |
10:58:37.20 |
-26:12:45.7 |
HIP 53658 |
6.11 |
| 2026-06-13 00:00 |
10:58:39.55 |
-26:11:57.6 |
HIP 53658 |
5.27 |
| 2026-06-13 12:00 |
10:58:41.96 |
-26:11:10.0 |
HIP 53658 |
4.48 |
| 2026-06-14 00:00 |
10:58:44.44 |
-26:10:22.8 |
HIP 53658 |
3.79 |
| 2026-06-14 12:00 |
10:58:46.98 |
-26:09:36.2 |
HIP 53658 |
3.26 |
| 2026-06-15 00:00 |
10:58:49.59 |
-26:08:50.0 |
HIP 53658 |
2.97 |
| 2026-06-15 12:00 |
10:58:52.26 |
-26:08:04.2 |
HIP 53658 |
2.99 |
| 2026-06-16 00:00 |
10:58:54.99 |
-26:07:19.0 |
HIP 53658 |
3.33 |
| 2026-06-16 12:00 |
10:58:57.79 |
-26:06:34.2 |
HIP 53658 |
3.90 |
| 2026-06-17 00:00 |
10:59:00.65 |
-26:05:50.0 |
HIP 53658 |
4.62 |
| 2026-06-17 12:00 |
10:59:03.58 |
-26:05:06.2 |
HIP 53658 |
5.44 |
| 2026-06-18 00:00 |
10:59:06.56 |
-26:04:22.9 |
HIP 53658 |
6.31 |
| 2026-06-18 12:00 |
10:59:09.61 |
-26:03:40.1 |
HIP 53658 |
7.22 |
| 2026-06-19 00:00 |
10:59:12.73 |
-26:02:57.8 |
HIP 53658 |
8.16 |
| 2026-06-19 12:00 |
10:59:15.90 |
-26:02:16.0 |
HIP 53658 |
9.12 |
| 2026-06-20 00:00 |
10:59:19.14 |
-26:01:34.7 |
HIP 53658 |
10.09 |
| 2026-06-20 12:00 |
10:59:22.43 |
-26:00:54.0 |
HIP 53658 |
11.07 |
| 2026-06-21 00:00 |
10:59:25.79 |
-26:00:13.7 |
HIP 53658 |
12.07 |
| 2026-06-21 12:00 |
10:59:29.21 |
-25:59:33.9 |
HIP 53658 |
13.08 |
| 2026-06-22 00:00 |
10:59:32.69 |
-25:58:54.6 |
HIP 53658 |
14.09 |