메타데이터
| 항목 |
값 |
| Designation |
C/1998 P1 (Williams) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1998-10-17T20:04:26.601600Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:57Z |
| Obs used |
403 |
| NEO |
- |
| M1 |
7.800 |
| K1 |
14.750 |
| PC |
0.030 |
Osculating 궤도요소
| 항목 |
값 |
| Epoch (epoch_cal, TDB) |
1998-12-15.0000000 |
| e |
0.99935941 |
| q (au) |
1.146154 |
| a (au) |
1789.224617 |
| i (deg) |
145.728519 |
| Ω (om, deg) |
156.373092 |
| ω (w, deg) |
294.452932 |
| M (ma, deg) |
0.000757 |
밝기
산란 + 전체 선형
$$
M_a = (6.727 + 4.174\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
모델 상수
| 항목 |
값 |
| H0 |
6.727 |
| n |
4.174 |
| gf |
0.891 |
| gb |
-0.729 |
| k |
0.993 |
| δ90 |
1.273 |
| 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 |
| 1998-08-10 |
1998-08-29 |
+48.4077 |
-7.973 |
| 1998-08-29 |
1998-10-04 |
-9.7163 |
+0.414 |
| 1998-11-14 |
1998-12-30 |
-0.7986 |
+0.004 |
| 1998-12-30 |
1999-01-17 |
-4.5488 |
+1.146 |
| 1999-01-17 |
1999-02-09 |
+3.1416 |
-0.885 |
| 1999-02-09 |
1999-03-04 |
+15.9071 |
-5.048 |
| 1999-03-04 |
1999-04-13 |
-6.4456 |
+2.729 |
| 1999-04-13 |
1999-05-18 |
-16.8421 |
+7.088 |
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 |
03:00:37.66 |
+52:23:28.4 |
HIP 14043 |
3.24 |
| 2026-07-29 12:00 |
03:00:38.27 |
+52:23:49.1 |
HIP 14043 |
3.44 |
| 2026-07-30 00:00 |
03:00:38.84 |
+52:24:09.8 |
HIP 14017 |
3.65 |
| 2026-07-30 12:00 |
03:00:39.38 |
+52:24:30.5 |
HIP 14017 |
3.41 |
| 2026-07-31 00:00 |
03:00:39.89 |
+52:24:51.2 |
HIP 14017 |
3.18 |
| 2026-07-31 12:00 |
03:00:40.37 |
+52:25:11.8 |
HIP 14017 |
2.98 |
| 2026-08-01 00:00 |
03:00:40.82 |
+52:25:32.4 |
HIP 14017 |
2.80 |
| 2026-08-01 12:00 |
03:00:41.24 |
+52:25:52.9 |
HIP 14017 |
2.66 |
| 2026-08-02 00:00 |
03:00:41.64 |
+52:26:13.4 |
HIP 14017 |
2.55 |
| 2026-08-02 12:00 |
03:00:42.00 |
+52:26:33.9 |
HIP 14017 |
2.48 |
| 2026-08-03 00:00 |
03:00:42.33 |
+52:26:54.4 |
HIP 14017 |
2.46 |
| 2026-08-03 12:00 |
03:00:42.63 |
+52:27:14.8 |
HIP 14017 |
2.47 |
| 2026-08-04 00:00 |
03:00:42.90 |
+52:27:35.1 |
HIP 14017 |
2.53 |
| 2026-08-04 12:00 |
03:00:43.14 |
+52:27:55.4 |
HIP 14017 |
2.63 |
| 2026-08-05 00:00 |
03:00:43.35 |
+52:28:15.7 |
HIP 14017 |
2.76 |
| 2026-08-05 12:00 |
03:00:43.53 |
+52:28:35.9 |
HIP 14017 |
2.92 |
| 2026-08-06 00:00 |
03:00:43.67 |
+52:28:56.1 |
HIP 14017 |
3.11 |
| 2026-08-06 12:00 |
03:00:43.79 |
+52:29:16.2 |
HIP 14017 |
3.31 |
| 2026-08-07 00:00 |
03:00:43.88 |
+52:29:36.3 |
HIP 14017 |
3.53 |
| 2026-08-07 12:00 |
03:00:43.93 |
+52:29:56.3 |
HIP 14017 |
3.77 |
| 2026-08-08 00:00 |
03:00:43.96 |
+52:30:16.3 |
HIP 14017 |
4.01 |
| 2026-08-08 12:00 |
03:00:43.95 |
+52:30:36.2 |
HIP 14017 |
4.26 |
| 2026-08-09 00:00 |
03:00:43.91 |
+52:30:56.1 |
HIP 14017 |
4.52 |
| 2026-08-09 12:00 |
03:00:43.84 |
+52:31:15.9 |
HIP 14017 |
4.79 |
| 2026-08-10 00:00 |
03:00:43.74 |
+52:31:35.6 |
HIP 14017 |
5.06 |
| 2026-08-10 12:00 |
03:00:43.61 |
+52:31:55.3 |
HIP 14017 |
5.33 |
| 2026-08-11 00:00 |
03:00:43.45 |
+52:32:15.0 |
HIP 14017 |
5.61 |
| 2026-08-11 12:00 |
03:00:43.26 |
+52:32:34.5 |
HIP 14017 |
5.88 |
| 2026-08-12 00:00 |
03:00:43.03 |
+52:32:54.0 |
HIP 14017 |
6.16 |
| 2026-08-12 12:00 |
03:00:42.77 |
+52:33:13.4 |
HIP 14017 |
6.44 |
| 2026-08-13 00:00 |
03:00:42.49 |
+52:33:32.8 |
HIP 14017 |
6.73 |
| 2026-08-13 12:00 |
03:00:42.17 |
+52:33:52.1 |
HIP 14017 |
7.01 |
| 2026-08-14 00:00 |
03:00:41.82 |
+52:34:11.3 |
HIP 14017 |
7.29 |
| 2026-08-14 12:00 |
03:00:41.43 |
+52:34:30.4 |
HIP 14017 |
7.58 |
| 2026-08-15 00:00 |
03:00:41.02 |
+52:34:49.5 |
HIP 14017 |
7.87 |
| 2026-08-15 12:00 |
03:00:40.58 |
+52:35:08.5 |
HIP 14017 |
8.15 |
| 2026-08-16 00:00 |
03:00:40.10 |
+52:35:27.4 |
HIP 14017 |
8.44 |
| 2026-08-16 12:00 |
03:00:39.59 |
+52:35:46.2 |
HIP 14017 |
8.72 |
| 2026-08-17 00:00 |
03:00:39.05 |
+52:36:04.9 |
HIP 14017 |
9.01 |
| 2026-08-17 12:00 |
03:00:38.48 |
+52:36:23.6 |
HIP 14017 |
9.30 |
| 2026-08-18 00:00 |
03:00:37.88 |
+52:36:42.2 |
HIP 14017 |
9.58 |
| 2026-08-18 12:00 |
03:00:37.25 |
+52:37:00.7 |
HIP 14017 |
9.87 |
| 2026-08-19 00:00 |
03:00:36.58 |
+52:37:19.1 |
HIP 14017 |
10.16 |