메타데이터
| 항목 |
값 |
| Designation |
C/2021 D1 (SWAN) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2021-02-27T14:36:45.581760Z |
| Orbit solution date (soln_date, UTC) |
2021-07-06T18:29:33Z |
| Obs used |
342 |
| NEO |
- |
| M1 |
13.300 |
| K1 |
14.500 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2021-02-28T17:29:51.648000Z |
| Discovery magnitude (MPC) |
14.60 R |
| Discovery observatory (MPC) |
K88 · GINOP-KHK, Piszkéstető |
Osculating 궤도요소
| 항목 |
값 |
| Epoch (epoch_cal, TDB) |
2021-03-19.0000000 |
| e |
0.99064883 |
| q (au) |
0.901798 |
| a (au) |
96.436853 |
| i (deg) |
31.460781 |
| Ω (om, deg) |
311.271222 |
| ω (w, deg) |
72.222962 |
| M (ma, deg) |
0.020181 |
밝기
산란 + 전체 선형
$$
M_a = (14.258 + 5.845\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
모델 상수
| 항목 |
값 |
| H0 |
14.258 |
| n |
5.845 |
| gf |
0.994 |
| gb |
-0.610 |
| 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 |
| 2021-02-28 |
2021-05-11 |
-0.4219 |
-0.927 |
log10 r = log10(태양거리/AU), Δ = 지구거리(AU)
천체력
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
10:50:02.02 |
-17:46:42.9 |
HIP 52954 |
12.65 |
| 2026-03-26 12:00 |
10:49:55.33 |
-17:45:51.0 |
HIP 52954 |
13.23 |
| 2026-03-27 00:00 |
10:49:48.66 |
-17:44:59.0 |
HIP 52954 |
14.02 |
| 2026-03-27 12:00 |
10:49:42.04 |
-17:44:06.7 |
HIP 52954 |
14.99 |
| 2026-03-28 00:00 |
10:49:35.44 |
-17:43:14.2 |
HIP 52954 |
16.11 |
| 2026-03-28 12:00 |
10:49:28.89 |
-17:42:21.5 |
HIP 52954 |
17.34 |
| 2026-03-29 00:00 |
10:49:22.37 |
-17:41:28.5 |
HIP 52954 |
18.67 |
| 2026-03-29 12:00 |
10:49:15.88 |
-17:40:35.4 |
HIP 52954 |
20.07 |
| 2026-03-30 00:00 |
10:49:09.44 |
-17:39:42.1 |
HIP 52954 |
21.52 |
| 2026-03-30 12:00 |
10:49:03.03 |
-17:38:48.5 |
HIP 52954 |
23.01 |
| 2026-03-31 00:00 |
10:48:56.66 |
-17:37:54.8 |
HIP 52954 |
24.54 |
| 2026-03-31 12:00 |
10:48:50.33 |
-17:37:00.9 |
HIP 52954 |
26.10 |
| 2026-04-01 00:00 |
10:48:44.03 |
-17:36:06.8 |
HIP 52752 |
24.81 |
| 2026-04-01 12:00 |
10:48:37.78 |
-17:35:12.5 |
HIP 52752 |
23.08 |
| 2026-04-02 00:00 |
10:48:31.57 |
-17:34:18.1 |
HIP 52752 |
21.35 |
| 2026-04-02 12:00 |
10:48:25.40 |
-17:33:23.5 |
HIP 52752 |
19.64 |
| 2026-04-03 00:00 |
10:48:19.26 |
-17:32:28.7 |
HIP 52752 |
17.93 |
| 2026-04-03 12:00 |
10:48:13.17 |
-17:31:33.8 |
HIP 52752 |
16.24 |
| 2026-04-04 00:00 |
10:48:07.13 |
-17:30:38.8 |
HIP 52752 |
14.56 |
| 2026-04-04 12:00 |
10:48:01.12 |
-17:29:43.6 |
HIP 52752 |
12.90 |
| 2026-04-05 00:00 |
10:47:55.16 |
-17:28:48.2 |
HIP 52752 |
11.26 |
| 2026-04-05 12:00 |
10:47:49.24 |
-17:27:52.8 |
HIP 52752 |
9.65 |
| 2026-04-06 00:00 |
10:47:43.37 |
-17:26:57.2 |
HIP 52752 |
8.08 |
| 2026-04-06 12:00 |
10:47:37.54 |
-17:26:01.5 |
HIP 52752 |
6.57 |
| 2026-04-07 00:00 |
10:47:31.75 |
-17:25:05.7 |
HIP 52752 |
5.18 |
| 2026-04-07 12:00 |
10:47:26.01 |
-17:24:09.8 |
HIP 52752 |
4.01 |
| 2026-04-08 00:00 |
10:47:20.32 |
-17:23:13.7 |
HIP 52752 |
3.29 |
| 2026-04-08 12:00 |
10:47:14.67 |
-17:22:17.6 |
HIP 52752 |
3.33 |
| 2026-04-09 00:00 |
10:47:09.07 |
-17:21:21.4 |
HIP 52752 |
4.09 |
| 2026-04-09 12:00 |
10:47:03.52 |
-17:20:25.1 |
HIP 52737 |
3.78 |
| 2026-04-10 00:00 |
10:46:58.01 |
-17:19:28.7 |
HIP 52737 |
2.19 |
| 2026-04-10 12:00 |
10:46:52.55 |
-17:18:32.2 |
HIP 52737 |
0.74 |
| 2026-04-11 00:00 |
10:46:47.15 |
-17:17:35.7 |
HIP 52737 |
1.19 |
| 2026-04-11 12:00 |
10:46:41.79 |
-17:16:39.1 |
HIP 52737 |
2.71 |
| 2026-04-12 00:00 |
10:46:36.47 |
-17:15:42.5 |
HIP 52737 |
4.27 |
| 2026-04-12 12:00 |
10:46:31.21 |
-17:14:45.8 |
HIP 52737 |
5.84 |
| 2026-04-13 00:00 |
10:46:26.00 |
-17:13:49.1 |
HIP 52737 |
7.39 |
| 2026-04-13 12:00 |
10:46:20.84 |
-17:12:52.3 |
HIP 52737 |
8.94 |
| 2026-04-14 00:00 |
10:46:15.73 |
-17:11:55.5 |
HIP 52641 |
8.11 |
| 2026-04-14 12:00 |
10:46:10.68 |
-17:10:58.7 |
HIP 52641 |
6.60 |
| 2026-04-15 00:00 |
10:46:05.67 |
-17:10:01.8 |
HIP 52641 |
5.10 |
| 2026-04-15 12:00 |
10:46:00.72 |
-17:09:04.9 |
HIP 52641 |
3.64 |
| 2026-04-16 00:00 |
10:45:55.82 |
-17:08:08.0 |
HIP 52641 |
2.25 |