메타데이터
| 항목 |
값 |
| Designation |
C/1987 P1 (Bradfield) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1987-11-07T06:34:43.440960Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:33Z |
| Obs used |
611 |
| NEO |
- |
| M1 |
6.000 |
| K1 |
8.500 |
| PC |
- |
Osculating 궤도요소
| 항목 |
값 |
| Epoch (epoch_cal, TDB) |
1987-11-29.0000000 |
| e |
0.99473713 |
| q (au) |
0.868956 |
| a (au) |
165.110625 |
| i (deg) |
34.088067 |
| Ω (om, deg) |
268.092924 |
| ω (w, deg) |
73.899611 |
| M (ma, deg) |
0.010093 |
밝기
산란 + 전체 선형
$$
M_a = (5.750 + 2.678\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
모델 상수
| 항목 |
값 |
| H0 |
5.750 |
| n |
2.678 |
| gf |
0.800 |
| gb |
-0.500 |
| 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
잔차 (구간 선형)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| 시작일 (UTC) |
끝 (UTC) |
a |
b |
| 1987-08-12 |
1987-11-06 |
+1.8670 |
+0.018 |
| 1987-11-07 |
1987-12-09 |
+1.4060 |
+0.081 |
| 1987-12-09 |
1988-03-08 |
-0.4160 |
+0.009 |
| 1988-03-08 |
1988-04-11 |
+8.3598 |
-2.815 |
log10 r = log10(태양거리/AU), Δ = 지구거리(AU)
천체력
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
09:12:02.36 |
-14:29:52.4 |
HIP 45263 |
24.65 |
| 2026-09-20 12:00 |
09:12:03.79 |
-14:30:08.2 |
HIP 45263 |
24.48 |
| 2026-09-21 00:00 |
09:12:05.21 |
-14:30:23.9 |
HIP 45263 |
24.32 |
| 2026-09-21 12:00 |
09:12:06.63 |
-14:30:39.7 |
HIP 45263 |
24.17 |
| 2026-09-22 00:00 |
09:12:08.03 |
-14:30:55.6 |
HIP 45263 |
24.02 |
| 2026-09-22 12:00 |
09:12:09.42 |
-14:31:11.5 |
HIP 45263 |
23.89 |
| 2026-09-23 00:00 |
09:12:10.80 |
-14:31:27.5 |
HIP 45263 |
23.76 |
| 2026-09-23 12:00 |
09:12:12.17 |
-14:31:43.5 |
HIP 45263 |
23.65 |
| 2026-09-24 00:00 |
09:12:13.52 |
-14:31:59.6 |
HIP 45263 |
23.55 |
| 2026-09-24 12:00 |
09:12:14.87 |
-14:32:15.7 |
HIP 45263 |
23.45 |
| 2026-09-25 00:00 |
09:12:16.20 |
-14:32:31.9 |
HIP 45263 |
23.37 |
| 2026-09-25 12:00 |
09:12:17.53 |
-14:32:48.0 |
HIP 45263 |
23.29 |
| 2026-09-26 00:00 |
09:12:18.84 |
-14:33:04.3 |
HIP 45263 |
23.23 |
| 2026-09-26 12:00 |
09:12:20.14 |
-14:33:20.6 |
HIP 45263 |
23.17 |
| 2026-09-27 00:00 |
09:12:21.43 |
-14:33:36.9 |
HIP 45263 |
23.13 |
| 2026-09-27 12:00 |
09:12:22.70 |
-14:33:53.2 |
HIP 45263 |
23.09 |
| 2026-09-28 00:00 |
09:12:23.97 |
-14:34:09.6 |
HIP 45263 |
23.07 |
| 2026-09-28 12:00 |
09:12:25.22 |
-14:34:26.1 |
HIP 45263 |
23.05 |
| 2026-09-29 00:00 |
09:12:26.46 |
-14:34:42.6 |
HIP 45263 |
23.05 |
| 2026-09-29 12:00 |
09:12:27.69 |
-14:34:59.1 |
HIP 45263 |
23.05 |
| 2026-09-30 00:00 |
09:12:28.90 |
-14:35:15.6 |
HIP 45263 |
23.06 |
| 2026-09-30 12:00 |
09:12:30.10 |
-14:35:32.2 |
HIP 45263 |
23.08 |
| 2026-10-01 00:00 |
09:12:31.29 |
-14:35:48.8 |
HIP 45305 |
22.97 |
| 2026-10-01 12:00 |
09:12:32.47 |
-14:36:05.4 |
HIP 45305 |
22.62 |
| 2026-10-02 00:00 |
09:12:33.64 |
-14:36:22.1 |
HIP 45305 |
22.28 |
| 2026-10-02 12:00 |
09:12:34.79 |
-14:36:38.8 |
HIP 45305 |
21.94 |
| 2026-10-03 00:00 |
09:12:35.93 |
-14:36:55.5 |
HIP 45305 |
21.61 |
| 2026-10-03 12:00 |
09:12:37.06 |
-14:37:12.3 |
HIP 45305 |
21.29 |
| 2026-10-04 00:00 |
09:12:38.17 |
-14:37:29.0 |
HIP 45305 |
20.97 |
| 2026-10-04 12:00 |
09:12:39.27 |
-14:37:45.8 |
HIP 45305 |
20.65 |
| 2026-10-05 00:00 |
09:12:40.36 |
-14:38:02.7 |
HIP 45305 |
20.34 |
| 2026-10-05 12:00 |
09:12:41.43 |
-14:38:19.5 |
HIP 45305 |
20.03 |
| 2026-10-06 00:00 |
09:12:42.49 |
-14:38:36.4 |
HIP 45305 |
19.74 |
| 2026-10-06 12:00 |
09:12:43.54 |
-14:38:53.3 |
HIP 45305 |
19.44 |
| 2026-10-07 00:00 |
09:12:44.57 |
-14:39:10.2 |
HIP 45305 |
19.16 |
| 2026-10-07 12:00 |
09:12:45.59 |
-14:39:27.1 |
HIP 45305 |
18.88 |
| 2026-10-08 00:00 |
09:12:46.60 |
-14:39:44.1 |
HIP 45305 |
18.60 |
| 2026-10-08 12:00 |
09:12:47.59 |
-14:40:01.0 |
HIP 45305 |
18.34 |
| 2026-10-09 00:00 |
09:12:48.57 |
-14:40:18.0 |
HIP 45305 |
18.08 |
| 2026-10-09 12:00 |
09:12:49.53 |
-14:40:35.0 |
HIP 45305 |
17.82 |
| 2026-10-10 00:00 |
09:12:50.48 |
-14:40:52.0 |
HIP 45305 |
17.58 |
| 2026-10-10 12:00 |
09:12:51.42 |
-14:41:09.0 |
HIP 45305 |
17.34 |
| 2026-10-11 00:00 |
09:12:52.34 |
-14:41:26.0 |
HIP 45305 |
17.11 |