메타데이터
| 항목 |
값 |
| Designation |
C/2017 Y2 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2020-11-04T13:33:04.429440Z |
| Orbit solution date (soln_date, UTC) |
2024-02-25T22:12:25Z |
| Obs used |
961 |
| NEO |
- |
| M1 |
8.600 |
| K1 |
8.000 |
| PC |
0.030 |
Osculating 궤도요소
| 항목 |
값 |
| Epoch (epoch_cal, TDB) |
2020-09-02.0000000 |
| e |
1.00096403 |
| q (au) |
4.632068 |
| a (au) |
-4804.896119 |
| i (deg) |
128.421418 |
| Ω (om, deg) |
65.986420 |
| ω (w, deg) |
147.860404 |
| M (ma, deg) |
-0.000188 |
밝기
산란 + 전체 선형
$$
M_a = (8.195 + 3.722\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
모델 상수
| 항목 |
값 |
| H0 |
8.195 |
| n |
3.722 |
| gf |
0.963 |
| gb |
-0.841 |
| k |
0.994 |
| 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 |
| 2017-12-24 |
2020-10-30 |
+1.7402 |
-1.104 |
| 2020-11-05 |
2022-02-23 |
-10.1087 |
+6.757 |
| 2022-02-23 |
2022-07-31 |
+14.3389 |
-12.242 |
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 |
09:50:36.93 |
-45:07:59.1 |
HIP 48383 |
12.43 |
| 2026-03-26 12:00 |
09:50:25.46 |
-45:06:19.1 |
HIP 48383 |
14.71 |
| 2026-03-27 00:00 |
09:50:14.07 |
-45:04:38.5 |
HIP 48383 |
17.08 |
| 2026-03-27 12:00 |
09:50:02.76 |
-45:02:57.3 |
HIP 48383 |
19.50 |
| 2026-03-28 00:00 |
09:49:51.54 |
-45:01:15.5 |
HIP 48383 |
21.96 |
| 2026-03-28 12:00 |
09:49:40.40 |
-44:59:33.1 |
HIP 48383 |
24.44 |
| 2026-03-29 00:00 |
09:49:29.35 |
-44:57:50.1 |
HIP 48383 |
26.94 |
| 2026-03-29 12:00 |
09:49:18.38 |
-44:56:06.6 |
HIP 48383 |
29.45 |
| 2026-03-30 00:00 |
09:49:07.50 |
-44:54:22.5 |
HIP 47963 |
29.30 |
| 2026-03-30 12:00 |
09:48:56.70 |
-44:52:37.8 |
HIP 47963 |
26.96 |
| 2026-03-31 00:00 |
09:48:46.00 |
-44:50:52.6 |
HIP 47963 |
24.69 |
| 2026-03-31 12:00 |
09:48:35.38 |
-44:49:06.9 |
HIP 47963 |
22.50 |
| 2026-04-01 00:00 |
09:48:24.85 |
-44:47:20.6 |
HIP 47963 |
20.42 |
| 2026-04-01 12:00 |
09:48:14.41 |
-44:45:33.9 |
HIP 47963 |
18.47 |
| 2026-04-02 00:00 |
09:48:04.06 |
-44:43:46.6 |
HIP 47963 |
16.70 |
| 2026-04-02 12:00 |
09:47:53.80 |
-44:41:58.9 |
HIP 47963 |
15.18 |
| 2026-04-03 00:00 |
09:47:43.63 |
-44:40:10.6 |
HIP 47963 |
13.99 |
| 2026-04-03 12:00 |
09:47:33.55 |
-44:38:21.9 |
HIP 47963 |
13.20 |
| 2026-04-04 00:00 |
09:47:23.56 |
-44:36:32.8 |
HIP 47963 |
12.89 |
| 2026-04-04 12:00 |
09:47:13.66 |
-44:34:43.2 |
HIP 47963 |
13.09 |
| 2026-04-05 00:00 |
09:47:03.86 |
-44:32:53.1 |
HIP 47963 |
13.77 |
| 2026-04-05 12:00 |
09:46:54.15 |
-44:31:02.6 |
HIP 47963 |
14.87 |
| 2026-04-06 00:00 |
09:46:44.53 |
-44:29:11.7 |
HIP 47918 |
15.78 |
| 2026-04-06 12:00 |
09:46:35.01 |
-44:27:20.4 |
HIP 47918 |
16.69 |
| 2026-04-07 00:00 |
09:46:25.58 |
-44:25:28.7 |
HIP 47918 |
17.93 |
| 2026-04-07 12:00 |
09:46:16.24 |
-44:23:36.6 |
HIP 47918 |
19.42 |
| 2026-04-08 00:00 |
09:46:07.00 |
-44:21:44.1 |
HIP 47918 |
21.10 |
| 2026-04-08 12:00 |
09:45:57.86 |
-44:19:51.2 |
HIP 47918 |
22.95 |
| 2026-04-09 00:00 |
09:45:48.81 |
-44:17:58.0 |
HIP 47765 |
22.02 |
| 2026-04-09 12:00 |
09:45:39.85 |
-44:16:04.4 |
HIP 47765 |
19.57 |
| 2026-04-10 00:00 |
09:45:30.99 |
-44:14:10.5 |
HIP 47765 |
17.14 |
| 2026-04-10 12:00 |
09:45:22.23 |
-44:12:16.2 |
HIP 47765 |
14.73 |
| 2026-04-11 00:00 |
09:45:13.57 |
-44:10:21.7 |
HIP 47765 |
12.35 |
| 2026-04-11 12:00 |
09:45:05.00 |
-44:08:26.8 |
HIP 47765 |
10.02 |
| 2026-04-12 00:00 |
09:44:56.54 |
-44:06:31.6 |
HIP 47765 |
7.79 |
| 2026-04-12 12:00 |
09:44:48.17 |
-44:04:36.1 |
HIP 47765 |
5.74 |
| 2026-04-13 00:00 |
09:44:39.89 |
-44:02:40.4 |
HIP 47765 |
4.17 |
| 2026-04-13 12:00 |
09:44:31.72 |
-44:00:44.4 |
HIP 47765 |
3.71 |
| 2026-04-14 00:00 |
09:44:23.65 |
-43:58:48.1 |
HIP 47765 |
4.69 |
| 2026-04-14 12:00 |
09:44:15.67 |
-43:56:51.6 |
HIP 47765 |
6.48 |
| 2026-04-15 00:00 |
09:44:07.80 |
-43:54:54.8 |
HIP 47765 |
8.58 |
| 2026-04-15 12:00 |
09:44:00.02 |
-43:52:57.8 |
HIP 47765 |
10.81 |
| 2026-04-16 00:00 |
09:43:52.35 |
-43:51:00.7 |
HIP 47765 |
13.10 |