메타데이터
| 항목 |
값 |
| Designation |
C/2021 C3 (Catalina) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2021-02-12T10:38:30.753600Z |
| Orbit solution date (soln_date, UTC) |
2024-06-21T13:42:16Z |
| Obs used |
363 |
| NEO |
- |
| M1 |
16.100 |
| K1 |
4.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2021-02-07T11:02:01.017600Z |
| Discovery magnitude (MPC) |
19.15 G |
| Discovery observatory (MPC) |
703 · University of Arizona Catalina Sky Survey |
Osculating 궤도요소
| 항목 |
값 |
| Epoch (epoch_cal, TDB) |
2021-03-28.0000000 |
| e |
0.96405640 |
| q (au) |
2.276500 |
| a (au) |
63.335351 |
| i (deg) |
122.161615 |
| Ω (om, deg) |
181.919832 |
| ω (w, deg) |
357.151666 |
| M (ma, deg) |
0.085170 |
밝기
산란 + 전체 선형
$$
M_a = (17.520 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
모델 상수
| 항목 |
값 |
| H0 |
17.520 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.650 |
| k |
0.800 |
| 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 |
| 2021-02-13 |
2021-06-09 |
-16.5522 |
+5.942 |
log10 r = log10(태양거리/AU), Δ = 지구거리(AU)
천체력
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
01:03:16.98 |
+48:15:41.0 |
HIP 4949 |
7.40 |
| 2026-07-29 12:00 |
01:03:12.75 |
+48:16:26.2 |
HIP 4949 |
6.92 |
| 2026-07-30 00:00 |
01:03:08.43 |
+48:17:10.8 |
HIP 4949 |
6.57 |
| 2026-07-30 12:00 |
01:03:04.02 |
+48:17:55.1 |
HIP 4949 |
6.39 |
| 2026-07-31 00:00 |
01:02:59.52 |
+48:18:38.8 |
HIP 4949 |
6.40 |
| 2026-07-31 12:00 |
01:02:54.93 |
+48:19:22.1 |
HIP 4949 |
6.59 |
| 2026-08-01 00:00 |
01:02:50.24 |
+48:20:04.8 |
HIP 4949 |
6.95 |
| 2026-08-01 12:00 |
01:02:45.47 |
+48:20:47.1 |
HIP 4949 |
7.47 |
| 2026-08-02 00:00 |
01:02:40.61 |
+48:21:28.9 |
HIP 4949 |
8.10 |
| 2026-08-02 12:00 |
01:02:35.66 |
+48:22:10.2 |
HIP 4857 |
7.34 |
| 2026-08-03 00:00 |
01:02:30.61 |
+48:22:51.0 |
HIP 4857 |
6.58 |
| 2026-08-03 12:00 |
01:02:25.48 |
+48:23:31.2 |
HIP 4857 |
5.92 |
| 2026-08-04 00:00 |
01:02:20.26 |
+48:24:11.0 |
HIP 4857 |
5.42 |
| 2026-08-04 12:00 |
01:02:14.95 |
+48:24:50.2 |
HIP 4857 |
5.12 |
| 2026-08-05 00:00 |
01:02:09.55 |
+48:25:28.9 |
HIP 4857 |
5.06 |
| 2026-08-05 12:00 |
01:02:04.06 |
+48:26:07.1 |
HIP 4857 |
5.25 |
| 2026-08-06 00:00 |
01:01:58.48 |
+48:26:44.7 |
HIP 4857 |
5.67 |
| 2026-08-06 12:00 |
01:01:52.82 |
+48:27:21.7 |
HIP 4857 |
6.29 |
| 2026-08-07 00:00 |
01:01:47.06 |
+48:27:58.3 |
HIP 4857 |
7.05 |
| 2026-08-07 12:00 |
01:01:41.22 |
+48:28:34.2 |
HIP 4857 |
7.91 |
| 2026-08-08 00:00 |
01:01:35.29 |
+48:29:09.6 |
HIP 4857 |
8.85 |
| 2026-08-08 12:00 |
01:01:29.27 |
+48:29:44.5 |
HIP 4857 |
9.85 |
| 2026-08-09 00:00 |
01:01:23.16 |
+48:30:18.7 |
HIP 4857 |
10.89 |
| 2026-08-09 12:00 |
01:01:16.97 |
+48:30:52.4 |
HIP 4857 |
11.96 |
| 2026-08-10 00:00 |
01:01:10.69 |
+48:31:25.5 |
HIP 4857 |
13.07 |
| 2026-08-10 12:00 |
01:01:04.32 |
+48:31:58.0 |
HIP 4857 |
14.20 |
| 2026-08-11 00:00 |
01:00:57.87 |
+48:32:29.9 |
HIP 4857 |
15.35 |
| 2026-08-11 12:00 |
01:00:51.33 |
+48:33:01.2 |
HIP 4857 |
16.51 |
| 2026-08-12 00:00 |
01:00:44.71 |
+48:33:31.9 |
HIP 4857 |
17.70 |
| 2026-08-12 12:00 |
01:00:38.00 |
+48:34:01.9 |
HIP 4857 |
18.89 |
| 2026-08-13 00:00 |
01:00:31.20 |
+48:34:31.4 |
HIP 4857 |
20.10 |
| 2026-08-13 12:00 |
01:00:24.33 |
+48:35:00.2 |
HIP 4857 |
21.33 |
| 2026-08-14 00:00 |
01:00:17.36 |
+48:35:28.4 |
HIP 4857 |
22.56 |
| 2026-08-14 12:00 |
01:00:10.32 |
+48:35:56.0 |
HIP 4637 |
22.93 |
| 2026-08-15 00:00 |
01:00:03.19 |
+48:36:22.9 |
HIP 4637 |
22.20 |
| 2026-08-15 12:00 |
00:59:55.98 |
+48:36:49.2 |
HIP 4637 |
21.52 |
| 2026-08-16 00:00 |
00:59:48.69 |
+48:37:14.8 |
HIP 4637 |
20.91 |
| 2026-08-16 12:00 |
00:59:41.32 |
+48:37:39.8 |
HIP 4637 |
20.38 |
| 2026-08-17 00:00 |
00:59:33.87 |
+48:38:04.1 |
HIP 4637 |
19.92 |
| 2026-08-17 12:00 |
00:59:26.33 |
+48:38:27.8 |
HIP 4591 |
19.10 |
| 2026-08-18 00:00 |
00:59:18.72 |
+48:38:50.7 |
HIP 4591 |
18.33 |
| 2026-08-18 12:00 |
00:59:11.03 |
+48:39:13.1 |
HIP 4591 |
17.62 |
| 2026-08-19 00:00 |
00:59:03.26 |
+48:39:34.7 |
HIP 4591 |
17.00 |