메타데이터
| 항목 |
값 |
| Designation |
C/2007 D2 (Spacewatch) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2006-11-24T08:05:07.175040Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:05Z |
| Obs used |
72 |
| NEO |
- |
| M1 |
18.600 |
| K1 |
4.500 |
| PC |
- |
Osculating 궤도요소
| 항목 |
값 |
| Epoch (epoch_cal, TDB) |
2007-02-25.0000000 |
| e |
0.97763484 |
| q (au) |
1.245656 |
| a (au) |
55.696245 |
| i (deg) |
178.618011 |
| Ω (om, deg) |
297.125793 |
| ω (w, deg) |
65.126637 |
| M (ma, deg) |
0.219721 |
밝기
산란 + 전체 선형
$$
M_a = (18.407 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
모델 상수
| 항목 |
값 |
| H0 |
18.407 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.715 |
| k |
0.989 |
| 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
천체력
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
04:37:24.50 |
+21:04:01.2 |
HIP 21604 |
25.88 |
| 2026-07-29 12:00 |
04:37:26.24 |
+21:04:03.9 |
HIP 21604 |
25.74 |
| 2026-07-30 00:00 |
04:37:27.95 |
+21:04:06.6 |
HIP 21604 |
25.60 |
| 2026-07-30 12:00 |
04:37:29.64 |
+21:04:09.2 |
HIP 21604 |
25.47 |
| 2026-07-31 00:00 |
04:37:31.31 |
+21:04:11.8 |
HIP 21604 |
25.34 |
| 2026-07-31 12:00 |
04:37:32.96 |
+21:04:14.3 |
HIP 21604 |
25.23 |
| 2026-08-01 00:00 |
04:37:34.58 |
+21:04:16.8 |
HIP 21604 |
25.12 |
| 2026-08-01 12:00 |
04:37:36.18 |
+21:04:19.2 |
HIP 21639 |
24.90 |
| 2026-08-02 00:00 |
04:37:37.76 |
+21:04:21.6 |
HIP 21639 |
24.67 |
| 2026-08-02 12:00 |
04:37:39.31 |
+21:04:23.9 |
HIP 21639 |
24.44 |
| 2026-08-03 00:00 |
04:37:40.84 |
+21:04:26.2 |
HIP 21639 |
24.22 |
| 2026-08-03 12:00 |
04:37:42.34 |
+21:04:28.4 |
HIP 21639 |
24.01 |
| 2026-08-04 00:00 |
04:37:43.82 |
+21:04:30.5 |
HIP 21639 |
23.80 |
| 2026-08-04 12:00 |
04:37:45.28 |
+21:04:32.7 |
HIP 21639 |
23.60 |
| 2026-08-05 00:00 |
04:37:46.72 |
+21:04:34.7 |
HIP 21639 |
23.41 |
| 2026-08-05 12:00 |
04:37:48.13 |
+21:04:36.7 |
HIP 21639 |
23.22 |
| 2026-08-06 00:00 |
04:37:49.51 |
+21:04:38.7 |
HIP 21639 |
23.04 |
| 2026-08-06 12:00 |
04:37:50.87 |
+21:04:40.6 |
HIP 21639 |
22.86 |
| 2026-08-07 00:00 |
04:37:52.21 |
+21:04:42.4 |
HIP 21639 |
22.69 |
| 2026-08-07 12:00 |
04:37:53.52 |
+21:04:44.2 |
HIP 21639 |
22.53 |
| 2026-08-08 00:00 |
04:37:54.81 |
+21:04:46.0 |
HIP 21639 |
22.37 |
| 2026-08-08 12:00 |
04:37:56.07 |
+21:04:47.7 |
HIP 21639 |
22.22 |
| 2026-08-09 00:00 |
04:37:57.30 |
+21:04:49.3 |
HIP 21639 |
22.07 |
| 2026-08-09 12:00 |
04:37:58.52 |
+21:04:50.9 |
HIP 21639 |
21.93 |
| 2026-08-10 00:00 |
04:37:59.70 |
+21:04:52.4 |
HIP 21639 |
21.79 |
| 2026-08-10 12:00 |
04:38:00.86 |
+21:04:53.9 |
HIP 21639 |
21.66 |
| 2026-08-11 00:00 |
04:38:02.00 |
+21:04:55.3 |
HIP 21639 |
21.54 |
| 2026-08-11 12:00 |
04:38:03.10 |
+21:04:56.7 |
HIP 21639 |
21.42 |
| 2026-08-12 00:00 |
04:38:04.19 |
+21:04:58.0 |
HIP 21639 |
21.30 |
| 2026-08-12 12:00 |
04:38:05.24 |
+21:04:59.3 |
HIP 21639 |
21.19 |
| 2026-08-13 00:00 |
04:38:06.27 |
+21:05:00.5 |
HIP 21639 |
21.08 |
| 2026-08-13 12:00 |
04:38:07.28 |
+21:05:01.6 |
HIP 21639 |
20.98 |
| 2026-08-14 00:00 |
04:38:08.26 |
+21:05:02.7 |
HIP 21639 |
20.89 |
| 2026-08-14 12:00 |
04:38:09.21 |
+21:05:03.7 |
HIP 21639 |
20.79 |
| 2026-08-15 00:00 |
04:38:10.13 |
+21:05:04.7 |
HIP 21639 |
20.70 |
| 2026-08-15 12:00 |
04:38:11.03 |
+21:05:05.6 |
HIP 21639 |
20.62 |
| 2026-08-16 00:00 |
04:38:11.90 |
+21:05:06.5 |
HIP 21639 |
20.54 |
| 2026-08-16 12:00 |
04:38:12.74 |
+21:05:07.3 |
HIP 21639 |
20.46 |
| 2026-08-17 00:00 |
04:38:13.56 |
+21:05:08.1 |
HIP 21639 |
20.39 |
| 2026-08-17 12:00 |
04:38:14.35 |
+21:05:08.8 |
HIP 21639 |
20.32 |
| 2026-08-18 00:00 |
04:38:15.11 |
+21:05:09.4 |
HIP 21639 |
20.25 |
| 2026-08-18 12:00 |
04:38:15.85 |
+21:05:10.0 |
HIP 21639 |
20.19 |
| 2026-08-19 00:00 |
04:38:16.56 |
+21:05:10.6 |
HIP 21639 |
20.12 |