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) |
| 2026-07-29 00:00 |
06:09:32.80 |
+50:24:01.3 |
HIP 29080 |
17.84 |
| 2026-07-29 12:00 |
06:09:40.14 |
+50:24:17.9 |
HIP 29080 |
18.61 |
| 2026-07-30 00:00 |
06:09:47.45 |
+50:24:34.7 |
HIP 29080 |
19.43 |
| 2026-07-30 12:00 |
06:09:54.73 |
+50:24:51.8 |
HIP 29080 |
20.27 |
| 2026-07-31 00:00 |
06:10:01.96 |
+50:25:09.0 |
HIP 29080 |
21.14 |
| 2026-07-31 12:00 |
06:10:09.17 |
+50:25:26.5 |
HIP 29080 |
22.03 |
| 2026-08-01 00:00 |
06:10:16.33 |
+50:25:44.2 |
HIP 29441 |
22.24 |
| 2026-08-01 12:00 |
06:10:23.46 |
+50:26:02.1 |
HIP 29441 |
21.46 |
| 2026-08-02 00:00 |
06:10:30.56 |
+50:26:20.2 |
HIP 29441 |
20.73 |
| 2026-08-02 12:00 |
06:10:37.61 |
+50:26:38.6 |
HIP 29441 |
20.04 |
| 2026-08-03 00:00 |
06:10:44.63 |
+50:26:57.2 |
HIP 29441 |
19.41 |
| 2026-08-03 12:00 |
06:10:51.61 |
+50:27:15.9 |
HIP 29441 |
18.84 |
| 2026-08-04 00:00 |
06:10:58.55 |
+50:27:34.9 |
HIP 29441 |
18.33 |
| 2026-08-04 12:00 |
06:11:05.45 |
+50:27:54.2 |
HIP 29484 |
17.62 |
| 2026-08-05 00:00 |
06:11:12.31 |
+50:28:13.6 |
HIP 29484 |
16.51 |
| 2026-08-05 12:00 |
06:11:19.13 |
+50:28:33.2 |
HIP 29484 |
15.40 |
| 2026-08-06 00:00 |
06:11:25.92 |
+50:28:53.1 |
HIP 29484 |
14.31 |
| 2026-08-06 12:00 |
06:11:32.66 |
+50:29:13.2 |
HIP 29484 |
13.22 |
| 2026-08-07 00:00 |
06:11:39.36 |
+50:29:33.4 |
HIP 29484 |
12.14 |
| 2026-08-07 12:00 |
06:11:46.01 |
+50:29:53.9 |
HIP 29484 |
11.08 |
| 2026-08-08 00:00 |
06:11:52.63 |
+50:30:14.6 |
HIP 29484 |
10.03 |
| 2026-08-08 12:00 |
06:11:59.20 |
+50:30:35.5 |
HIP 29484 |
8.99 |
| 2026-08-09 00:00 |
06:12:05.73 |
+50:30:56.7 |
HIP 29484 |
7.97 |
| 2026-08-09 12:00 |
06:12:12.22 |
+50:31:18.0 |
HIP 29484 |
6.99 |
| 2026-08-10 00:00 |
06:12:18.66 |
+50:31:39.5 |
HIP 29484 |
6.03 |
| 2026-08-10 12:00 |
06:12:25.06 |
+50:32:01.3 |
HIP 29484 |
5.14 |
| 2026-08-11 00:00 |
06:12:31.42 |
+50:32:23.2 |
HIP 29484 |
4.32 |
| 2026-08-11 12:00 |
06:12:37.72 |
+50:32:45.4 |
HIP 29484 |
3.64 |
| 2026-08-12 00:00 |
06:12:43.99 |
+50:33:07.7 |
HIP 29484 |
3.18 |
| 2026-08-12 12:00 |
06:12:50.20 |
+50:33:30.3 |
HIP 29484 |
3.03 |
| 2026-08-13 00:00 |
06:12:56.37 |
+50:33:53.0 |
HIP 29484 |
3.23 |
| 2026-08-13 12:00 |
06:13:02.50 |
+50:34:16.0 |
HIP 29484 |
3.71 |
| 2026-08-14 00:00 |
06:13:08.58 |
+50:34:39.1 |
HIP 29484 |
4.39 |
| 2026-08-14 12:00 |
06:13:14.60 |
+50:35:02.5 |
HIP 29484 |
5.18 |
| 2026-08-15 00:00 |
06:13:20.58 |
+50:35:26.0 |
HIP 29484 |
6.04 |
| 2026-08-15 12:00 |
06:13:26.52 |
+50:35:49.8 |
HIP 29484 |
6.93 |
| 2026-08-16 00:00 |
06:13:32.40 |
+50:36:13.7 |
HIP 29484 |
7.85 |
| 2026-08-16 12:00 |
06:13:38.23 |
+50:36:37.9 |
HIP 29484 |
8.78 |
| 2026-08-17 00:00 |
06:13:44.02 |
+50:37:02.2 |
HIP 29484 |
9.72 |
| 2026-08-17 12:00 |
06:13:49.75 |
+50:37:26.7 |
HIP 29484 |
10.66 |
| 2026-08-18 00:00 |
06:13:55.44 |
+50:37:51.4 |
HIP 29623 |
10.48 |
| 2026-08-18 12:00 |
06:14:01.07 |
+50:38:16.3 |
HIP 29623 |
9.65 |
| 2026-08-19 00:00 |
06:14:06.65 |
+50:38:41.3 |
HIP 29623 |
8.86 |