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
$$
M_a = (8.196 + 3.722\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
모델 상수
| 항목 |
값 |
| H0 |
8.196 |
| n |
3.722 |
| gf |
0.956 |
| gb |
-0.841 |
| k |
0.994 |
| δ90 |
9.998 |
| 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) |
| 2026-07-29 00:00 |
09:48:02.79 |
-39:06:14.1 |
HIP 47983 |
19.46 |
| 2026-07-29 12:00 |
09:48:09.73 |
-39:06:00.9 |
HIP 47983 |
20.61 |
| 2026-07-30 00:00 |
09:48:16.68 |
-39:05:48.5 |
HIP 47983 |
21.77 |
| 2026-07-30 12:00 |
09:48:23.66 |
-39:05:36.8 |
HIP 48233 |
20.80 |
| 2026-07-31 00:00 |
09:48:30.65 |
-39:05:26.0 |
HIP 48233 |
19.49 |
| 2026-07-31 12:00 |
09:48:37.66 |
-39:05:15.9 |
HIP 48233 |
18.19 |
| 2026-08-01 00:00 |
09:48:44.69 |
-39:05:06.6 |
HIP 48233 |
16.90 |
| 2026-08-01 12:00 |
09:48:51.74 |
-39:04:58.0 |
HIP 48233 |
15.64 |
| 2026-08-02 00:00 |
09:48:58.79 |
-39:04:50.2 |
HIP 48233 |
14.40 |
| 2026-08-02 12:00 |
09:49:05.87 |
-39:04:43.2 |
HIP 48233 |
13.19 |
| 2026-08-03 00:00 |
09:49:12.96 |
-39:04:36.9 |
HIP 48233 |
12.02 |
| 2026-08-03 12:00 |
09:49:20.06 |
-39:04:31.5 |
HIP 48233 |
10.91 |
| 2026-08-04 00:00 |
09:49:27.18 |
-39:04:26.7 |
HIP 48233 |
9.87 |
| 2026-08-04 12:00 |
09:49:34.31 |
-39:04:22.8 |
HIP 48233 |
8.94 |
| 2026-08-05 00:00 |
09:49:41.45 |
-39:04:19.6 |
HIP 48233 |
8.15 |
| 2026-08-05 12:00 |
09:49:48.60 |
-39:04:17.2 |
HIP 48233 |
7.55 |
| 2026-08-06 00:00 |
09:49:55.77 |
-39:04:15.5 |
HIP 48233 |
7.18 |
| 2026-08-06 12:00 |
09:50:02.95 |
-39:04:14.6 |
HIP 48233 |
7.08 |
| 2026-08-07 00:00 |
09:50:10.13 |
-39:04:14.5 |
HIP 48233 |
7.27 |
| 2026-08-07 12:00 |
09:50:17.33 |
-39:04:15.1 |
HIP 48233 |
7.72 |
| 2026-08-08 00:00 |
09:50:24.54 |
-39:04:16.5 |
HIP 48233 |
8.40 |
| 2026-08-08 12:00 |
09:50:31.76 |
-39:04:18.6 |
HIP 48233 |
9.25 |
| 2026-08-09 00:00 |
09:50:38.98 |
-39:04:21.5 |
HIP 48233 |
10.23 |
| 2026-08-09 12:00 |
09:50:46.21 |
-39:04:25.2 |
HIP 48233 |
11.31 |
| 2026-08-10 00:00 |
09:50:53.45 |
-39:04:29.6 |
HIP 48233 |
12.47 |
| 2026-08-10 12:00 |
09:51:00.70 |
-39:04:34.8 |
HIP 48233 |
13.68 |
| 2026-08-11 00:00 |
09:51:07.95 |
-39:04:40.7 |
HIP 48301 |
14.55 |
| 2026-08-11 12:00 |
09:51:15.21 |
-39:04:47.4 |
HIP 48301 |
15.05 |
| 2026-08-12 00:00 |
09:51:22.47 |
-39:04:54.8 |
HIP 48301 |
15.67 |
| 2026-08-12 12:00 |
09:51:29.74 |
-39:05:03.0 |
HIP 48301 |
16.40 |
| 2026-08-13 00:00 |
09:51:37.01 |
-39:05:12.0 |
HIP 48301 |
17.23 |
| 2026-08-13 12:00 |
09:51:44.29 |
-39:05:21.6 |
HIP 48301 |
18.14 |
| 2026-08-14 00:00 |
09:51:51.57 |
-39:05:32.1 |
HIP 48301 |
19.12 |
| 2026-08-14 12:00 |
09:51:58.85 |
-39:05:43.2 |
HIP 48301 |
20.17 |
| 2026-08-15 00:00 |
09:52:06.13 |
-39:05:55.2 |
HIP 48301 |
21.27 |
| 2026-08-15 12:00 |
09:52:13.41 |
-39:06:07.8 |
HIP 48301 |
22.42 |
| 2026-08-16 00:00 |
09:52:20.69 |
-39:06:21.2 |
HIP 48301 |
23.60 |
| 2026-08-16 12:00 |
09:52:27.97 |
-39:06:35.3 |
HIP 48301 |
24.82 |
| 2026-08-17 00:00 |
09:52:35.26 |
-39:06:50.2 |
HIP 48301 |
26.07 |
| 2026-08-17 12:00 |
09:52:42.54 |
-39:07:05.7 |
HIP 48301 |
27.35 |
| 2026-08-18 00:00 |
09:52:49.81 |
-39:07:22.1 |
HIP 48301 |
28.64 |
| 2026-08-18 12:00 |
09:52:57.09 |
-39:07:39.1 |
HIP 48301 |
29.96 |
| 2026-08-19 00:00 |
09:53:04.36 |
-39:07:56.8 |
HIP 48653 |
28.94 |