메타데이터
| 항목 |
값 |
| Designation |
C/2015 ER61 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2017-05-09T22:39:09.815040Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:07Z |
| Obs used |
2826 |
| NEO |
- |
| M1 |
10.700 |
| K1 |
5.750 |
| PC |
- |
Osculating 궤도요소
| 항목 |
값 |
| Epoch (epoch_cal, TDB) |
2017-04-30.0000000 |
| e |
0.99727861 |
| q (au) |
1.042132 |
| a (au) |
382.940360 |
| i (deg) |
6.348649 |
| Ω (om, deg) |
235.221741 |
| ω (w, deg) |
68.192259 |
| M (ma, deg) |
359.998692 |
밝기
산란 + 전체 선형
$$
M_a = (6.320 + 4.711\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
모델 상수
| 항목 |
값 |
| H0 |
6.320 |
| n |
4.711 |
| gf |
0.992 |
| gb |
-0.804 |
| k |
0.997 |
| δ90 |
9.979 |
| 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 |
| 2016-02-04 |
2017-05-08 |
-1.6782 |
-0.087 |
| 2017-05-13 |
2018-02-24 |
-0.6062 |
+0.657 |
log10 r = log10(태양거리/AU), Δ = 지구거리(AU)
천체력
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
06:30:54.62 |
+18:57:47.2 |
HIP 31014 |
20.28 |
| 2026-05-12 12:00 |
06:30:58.54 |
+18:57:47.8 |
HIP 31014 |
20.57 |
| 2026-05-13 00:00 |
06:31:02.49 |
+18:57:48.4 |
HIP 31014 |
20.90 |
| 2026-05-13 12:00 |
06:31:06.47 |
+18:57:48.9 |
HIP 31014 |
21.27 |
| 2026-05-14 00:00 |
06:31:10.47 |
+18:57:49.3 |
HIP 31014 |
21.67 |
| 2026-05-14 12:00 |
06:31:14.51 |
+18:57:49.6 |
HIP 31014 |
22.12 |
| 2026-05-15 00:00 |
06:31:18.57 |
+18:57:49.9 |
HIP 31014 |
22.60 |
| 2026-05-15 12:00 |
06:31:22.66 |
+18:57:50.1 |
HIP 31014 |
23.11 |
| 2026-05-16 00:00 |
06:31:26.78 |
+18:57:50.3 |
HIP 31014 |
23.66 |
| 2026-05-16 12:00 |
06:31:30.92 |
+18:57:50.4 |
HIP 31014 |
24.23 |
| 2026-05-17 00:00 |
06:31:35.09 |
+18:57:50.4 |
HIP 31014 |
24.84 |
| 2026-05-17 12:00 |
06:31:39.29 |
+18:57:50.4 |
HIP 31014 |
25.48 |
| 2026-05-18 00:00 |
06:31:43.51 |
+18:57:50.3 |
HIP 31258 |
25.66 |
| 2026-05-18 12:00 |
06:31:47.76 |
+18:57:50.1 |
HIP 31258 |
24.75 |
| 2026-05-19 00:00 |
06:31:52.03 |
+18:57:49.9 |
HIP 31258 |
23.84 |
| 2026-05-19 12:00 |
06:31:56.33 |
+18:57:49.6 |
HIP 31258 |
22.94 |
| 2026-05-20 00:00 |
06:32:00.65 |
+18:57:49.2 |
HIP 31258 |
22.04 |
| 2026-05-20 12:00 |
06:32:05.00 |
+18:57:48.8 |
HIP 31258 |
21.15 |
| 2026-05-21 00:00 |
06:32:09.38 |
+18:57:48.3 |
HIP 31258 |
20.26 |
| 2026-05-21 12:00 |
06:32:13.77 |
+18:57:47.8 |
HIP 31258 |
19.39 |
| 2026-05-22 00:00 |
06:32:18.19 |
+18:57:47.2 |
HIP 31258 |
18.52 |
| 2026-05-22 12:00 |
06:32:22.63 |
+18:57:46.5 |
HIP 31261 |
17.66 |
| 2026-05-23 00:00 |
06:32:27.10 |
+18:57:45.8 |
HIP 31261 |
16.80 |
| 2026-05-23 12:00 |
06:32:31.59 |
+18:57:45.0 |
HIP 31261 |
15.97 |
| 2026-05-24 00:00 |
06:32:36.10 |
+18:57:44.1 |
HIP 31261 |
15.16 |
| 2026-05-24 12:00 |
06:32:40.63 |
+18:57:43.2 |
HIP 31261 |
14.37 |
| 2026-05-25 00:00 |
06:32:45.19 |
+18:57:42.2 |
HIP 31261 |
13.63 |
| 2026-05-25 12:00 |
06:32:49.76 |
+18:57:41.1 |
HIP 31261 |
12.92 |
| 2026-05-26 00:00 |
06:32:54.36 |
+18:57:40.0 |
HIP 31261 |
12.27 |
| 2026-05-26 12:00 |
06:32:58.98 |
+18:57:38.8 |
HIP 31261 |
11.68 |
| 2026-05-27 00:00 |
06:33:03.61 |
+18:57:37.6 |
HIP 31261 |
11.17 |
| 2026-05-27 12:00 |
06:33:08.27 |
+18:57:36.2 |
HIP 31261 |
10.73 |
| 2026-05-28 00:00 |
06:33:12.95 |
+18:57:34.9 |
HIP 31261 |
10.40 |
| 2026-05-28 12:00 |
06:33:17.65 |
+18:57:33.4 |
HIP 31261 |
10.17 |
| 2026-05-29 00:00 |
06:33:22.36 |
+18:57:31.9 |
HIP 31261 |
10.06 |
| 2026-05-29 12:00 |
06:33:27.10 |
+18:57:30.4 |
HIP 31261 |
10.08 |
| 2026-05-30 00:00 |
06:33:31.85 |
+18:57:28.7 |
HIP 31261 |
10.21 |
| 2026-05-30 12:00 |
06:33:36.63 |
+18:57:27.0 |
HIP 31261 |
10.47 |
| 2026-05-31 00:00 |
06:33:41.42 |
+18:57:25.3 |
HIP 31261 |
10.84 |
| 2026-05-31 12:00 |
06:33:46.22 |
+18:57:23.5 |
HIP 31261 |
11.31 |
| 2026-06-01 00:00 |
06:33:51.05 |
+18:57:21.6 |
HIP 31261 |
11.88 |
| 2026-06-01 12:00 |
06:33:55.90 |
+18:57:19.6 |
HIP 31261 |
12.52 |
| 2026-06-02 00:00 |
06:34:00.76 |
+18:57:17.6 |
HIP 31261 |
13.24 |