메타데이터
| 항목 |
값 |
| Designation |
C/2017 D2 (Barros) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2017-07-14T12:49:04.209600Z |
| Orbit solution date (soln_date, UTC) |
2024-12-12T17:11:30Z |
| Obs used |
433 |
| NEO |
- |
| M1 |
13.600 |
| K1 |
5.250 |
| PC |
- |
Osculating 궤도요소
| 항목 |
값 |
| Epoch (epoch_cal, TDB) |
2017-08-10.0000000 |
| e |
0.99819913 |
| q (au) |
2.485874 |
| a (au) |
1380.371396 |
| i (deg) |
31.265640 |
| Ω (om, deg) |
331.042014 |
| ω (w, deg) |
334.339752 |
| M (ma, deg) |
0.000509 |
밝기
산란 + 전체 선형
$$
M_a = (12.809 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
모델 상수
| 항목 |
값 |
| H0 |
12.809 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.502 |
| k |
1.000 |
| 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
잔차 (구간 선형)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| 시작일 (UTC) |
끝 (UTC) |
a |
b |
| 2017-02-23 |
2017-07-07 |
-12.4888 |
+4.968 |
| 2017-07-16 |
2018-10-10 |
+1.2813 |
-0.500 |
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 |
06:18:03.40 |
+51:10:46.6 |
HIP 30082 |
20.21 |
| 2026-09-20 12:00 |
06:18:05.00 |
+51:11:20.5 |
HIP 30082 |
20.33 |
| 2026-09-21 00:00 |
06:18:06.53 |
+51:11:54.4 |
HIP 30082 |
20.48 |
| 2026-09-21 12:00 |
06:18:08.00 |
+51:12:28.4 |
HIP 30082 |
20.66 |
| 2026-09-22 00:00 |
06:18:09.39 |
+51:13:02.4 |
HIP 30082 |
20.86 |
| 2026-09-22 12:00 |
06:18:10.72 |
+51:13:36.6 |
HIP 30082 |
21.09 |
| 2026-09-23 00:00 |
06:18:11.97 |
+51:14:10.7 |
HIP 30082 |
21.34 |
| 2026-09-23 12:00 |
06:18:13.16 |
+51:14:45.0 |
HIP 30082 |
21.61 |
| 2026-09-24 00:00 |
06:18:14.27 |
+51:15:19.2 |
HIP 30082 |
21.90 |
| 2026-09-24 12:00 |
06:18:15.31 |
+51:15:53.6 |
HIP 30082 |
22.22 |
| 2026-09-25 00:00 |
06:18:16.29 |
+51:16:28.0 |
HIP 30082 |
22.55 |
| 2026-09-25 12:00 |
06:18:17.19 |
+51:17:02.4 |
HIP 30082 |
22.90 |
| 2026-09-26 00:00 |
06:18:18.02 |
+51:17:36.9 |
HIP 30082 |
23.27 |
| 2026-09-26 12:00 |
06:18:18.78 |
+51:18:11.4 |
HIP 30082 |
23.65 |
| 2026-09-27 00:00 |
06:18:19.47 |
+51:18:46.0 |
HIP 30082 |
24.05 |
| 2026-09-27 12:00 |
06:18:20.09 |
+51:19:20.6 |
HIP 30082 |
24.47 |
| 2026-09-28 00:00 |
06:18:20.64 |
+51:19:55.2 |
HIP 30082 |
24.90 |
| 2026-09-28 12:00 |
06:18:21.11 |
+51:20:29.9 |
HIP 30082 |
25.34 |
| 2026-09-29 00:00 |
06:18:21.51 |
+51:21:04.6 |
HIP 30082 |
25.79 |
| 2026-09-29 12:00 |
06:18:21.85 |
+51:21:39.3 |
HIP 30082 |
26.25 |
| 2026-09-30 00:00 |
06:18:22.11 |
+51:22:14.1 |
HIP 30082 |
26.73 |
| 2026-09-30 12:00 |
06:18:22.29 |
+51:22:48.9 |
HIP 30082 |
27.21 |
| 2026-10-01 00:00 |
06:18:22.41 |
+51:23:23.7 |
HIP 30082 |
27.71 |
| 2026-10-01 12:00 |
06:18:22.45 |
+51:23:58.5 |
HIP 30082 |
28.21 |
| 2026-10-02 00:00 |
06:18:22.43 |
+51:24:33.3 |
HIP 30082 |
28.72 |
| 2026-10-02 12:00 |
06:18:22.33 |
+51:25:08.2 |
HIP 30082 |
29.24 |
| 2026-10-03 00:00 |
06:18:22.15 |
+51:25:43.0 |
HIP 30082 |
29.77 |
| 2026-10-03 12:00 |
06:18:21.91 |
+51:26:17.9 |
HIP 30082 |
30.31 |
| 2026-10-04 00:00 |
06:18:21.59 |
+51:26:52.8 |
HIP 30082 |
30.85 |
| 2026-10-04 12:00 |
06:18:21.19 |
+51:27:27.6 |
HIP 30198 |
30.86 |
| 2026-10-05 00:00 |
06:18:20.73 |
+51:28:02.5 |
HIP 30198 |
30.62 |
| 2026-10-05 12:00 |
06:18:20.19 |
+51:28:37.4 |
HIP 30198 |
30.40 |
| 2026-10-06 00:00 |
06:18:19.58 |
+51:29:12.2 |
HIP 30198 |
30.20 |
| 2026-10-06 12:00 |
06:18:18.90 |
+51:29:47.1 |
HIP 30198 |
30.02 |
| 2026-10-07 00:00 |
06:18:18.14 |
+51:30:21.9 |
HIP 30198 |
29.86 |
| 2026-10-07 12:00 |
06:18:17.31 |
+51:30:56.7 |
HIP 30198 |
29.73 |
| 2026-10-08 00:00 |
06:18:16.40 |
+51:31:31.5 |
HIP 30198 |
29.61 |
| 2026-10-08 12:00 |
06:18:15.43 |
+51:32:06.3 |
HIP 30198 |
29.52 |
| 2026-10-09 00:00 |
06:18:14.37 |
+51:32:41.1 |
HIP 30198 |
29.45 |
| 2026-10-09 12:00 |
06:18:13.25 |
+51:33:15.8 |
HIP 30198 |
29.40 |
| 2026-10-10 00:00 |
06:18:12.05 |
+51:33:50.5 |
HIP 30198 |
29.38 |
| 2026-10-10 12:00 |
06:18:10.78 |
+51:34:25.1 |
HIP 30198 |
29.38 |
| 2026-10-11 00:00 |
06:18:09.44 |
+51:34:59.7 |
HIP 30198 |
29.40 |