메타데이터
| 항목 |
값 |
| Designation |
C/2021 C4 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2021-01-17T01:15:25.960320Z |
| Orbit solution date (soln_date, UTC) |
2025-10-28T16:12:33Z |
| Obs used |
234 |
| NEO |
- |
| M1 |
6.900 |
| K1 |
13.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2021-02-12T14:39:53.769600Z |
| Discovery magnitude (MPC) |
18.73 c |
| Discovery observatory (MPC) |
T05 · ATLAS-HKO, Haleakala |
Osculating 궤도요소
| 항목 |
값 |
| Epoch (epoch_cal, TDB) |
2021-06-12.0000000 |
| e |
0.99919682 |
| q (au) |
4.504185 |
| a (au) |
5607.929825 |
| i (deg) |
132.842626 |
| Ω (om, deg) |
194.276215 |
| ω (w, deg) |
320.231119 |
| M (ma, deg) |
0.000343 |
밝기
산란 + 전체 선형
$$
M_a = (5.414 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
모델 상수
| 항목 |
값 |
| H0 |
5.414 |
| n |
6.000 |
| gf |
0.942 |
| gb |
-0.980 |
| k |
1.000 |
| δ90 |
1.000 |
| 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
천체력
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
09:48:49.42 |
+59:02:56.9 |
HIP 48319 |
16.76 |
| 2026-06-01 12:00 |
09:48:51.08 |
+59:01:43.6 |
HIP 48319 |
16.56 |
| 2026-06-02 00:00 |
09:48:52.86 |
+59:00:30.3 |
HIP 48319 |
16.42 |
| 2026-06-02 12:00 |
09:48:54.75 |
+58:59:17.1 |
HIP 48319 |
16.37 |
| 2026-06-03 00:00 |
09:48:56.75 |
+58:58:04.0 |
HIP 48319 |
16.40 |
| 2026-06-03 12:00 |
09:48:58.87 |
+58:56:50.9 |
HIP 48319 |
16.50 |
| 2026-06-04 00:00 |
09:49:01.10 |
+58:55:37.9 |
HIP 48319 |
16.69 |
| 2026-06-04 12:00 |
09:49:03.45 |
+58:54:25.0 |
HIP 48319 |
16.95 |
| 2026-06-05 00:00 |
09:49:05.91 |
+58:53:12.1 |
HIP 48319 |
17.28 |
| 2026-06-05 12:00 |
09:49:08.48 |
+58:51:59.3 |
HIP 48319 |
17.69 |
| 2026-06-06 00:00 |
09:49:11.15 |
+58:50:46.7 |
HIP 48319 |
18.16 |
| 2026-06-06 12:00 |
09:49:13.94 |
+58:49:34.1 |
HIP 48319 |
18.69 |
| 2026-06-07 00:00 |
09:49:16.84 |
+58:48:21.6 |
HIP 48319 |
19.28 |
| 2026-06-07 12:00 |
09:49:19.85 |
+58:47:09.2 |
HIP 48319 |
19.92 |
| 2026-06-08 00:00 |
09:49:22.96 |
+58:45:56.9 |
HIP 48319 |
20.61 |
| 2026-06-08 12:00 |
09:49:26.19 |
+58:44:44.8 |
HIP 48319 |
21.35 |
| 2026-06-09 00:00 |
09:49:29.52 |
+58:43:32.7 |
HIP 48319 |
22.12 |
| 2026-06-09 12:00 |
09:49:32.95 |
+58:42:20.8 |
HIP 48319 |
22.93 |
| 2026-06-10 00:00 |
09:49:36.49 |
+58:41:09.0 |
HIP 48319 |
23.77 |
| 2026-06-10 12:00 |
09:49:40.14 |
+58:39:57.4 |
HIP 48319 |
24.64 |
| 2026-06-11 00:00 |
09:49:43.89 |
+58:38:45.8 |
HIP 48319 |
25.54 |
| 2026-06-11 12:00 |
09:49:47.74 |
+58:37:34.5 |
HIP 48319 |
26.46 |
| 2026-06-12 00:00 |
09:49:51.70 |
+58:36:23.2 |
HIP 48319 |
27.41 |
| 2026-06-12 12:00 |
09:49:55.75 |
+58:35:12.2 |
HIP 48319 |
28.38 |
| 2026-06-13 00:00 |
09:49:59.91 |
+58:34:01.3 |
HIP 48319 |
29.36 |
| 2026-06-13 12:00 |
09:50:04.17 |
+58:32:50.5 |
HIP 48319 |
30.37 |
| 2026-06-14 00:00 |
09:50:08.53 |
+58:31:40.0 |
HIP 48319 |
31.39 |
| 2026-06-14 12:00 |
09:50:12.99 |
+58:30:29.6 |
HIP 48319 |
32.42 |
| 2026-06-15 00:00 |
09:50:17.55 |
+58:29:19.4 |
HIP 48319 |
33.47 |
| 2026-06-15 12:00 |
09:50:22.21 |
+58:28:09.3 |
HIP 48319 |
34.53 |
| 2026-06-16 00:00 |
09:50:26.96 |
+58:26:59.5 |
HIP 48510 |
35.51 |
| 2026-06-16 12:00 |
09:50:31.81 |
+58:25:49.9 |
HIP 48510 |
34.25 |
| 2026-06-17 00:00 |
09:50:36.75 |
+58:24:40.4 |
HIP 48510 |
32.98 |
| 2026-06-17 12:00 |
09:50:41.79 |
+58:23:31.2 |
HIP 48510 |
31.70 |
| 2026-06-18 00:00 |
09:50:46.92 |
+58:22:22.2 |
HIP 48510 |
30.43 |
| 2026-06-18 12:00 |
09:50:52.14 |
+58:21:13.4 |
HIP 48510 |
29.15 |
| 2026-06-19 00:00 |
09:50:57.46 |
+58:20:04.9 |
HIP 48510 |
27.87 |
| 2026-06-19 12:00 |
09:51:02.87 |
+58:18:56.5 |
HIP 48510 |
26.59 |
| 2026-06-20 00:00 |
09:51:08.37 |
+58:17:48.4 |
HIP 48510 |
25.31 |
| 2026-06-20 12:00 |
09:51:13.95 |
+58:16:40.6 |
HIP 48510 |
24.03 |
| 2026-06-21 00:00 |
09:51:19.63 |
+58:15:32.9 |
HIP 48510 |
22.75 |
| 2026-06-21 12:00 |
09:51:25.39 |
+58:14:25.6 |
HIP 48510 |
21.47 |
| 2026-06-22 00:00 |
09:51:31.24 |
+58:13:18.4 |
HIP 48510 |
20.20 |