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) |
| 2026-06-01 00:00 |
05:53:17.69 |
+50:19:03.9 |
HIP 27871 |
25.64 |
| 2026-06-01 12:00 |
05:53:26.15 |
+50:18:52.2 |
HIP 27871 |
25.58 |
| 2026-06-02 00:00 |
05:53:34.63 |
+50:18:40.7 |
HIP 27871 |
25.58 |
| 2026-06-02 12:00 |
05:53:43.12 |
+50:18:29.5 |
HIP 27871 |
25.66 |
| 2026-06-03 00:00 |
05:53:51.63 |
+50:18:18.5 |
HIP 27871 |
25.80 |
| 2026-06-03 12:00 |
05:54:00.15 |
+50:18:07.8 |
HIP 27871 |
26.01 |
| 2026-06-04 00:00 |
05:54:08.69 |
+50:17:57.3 |
HIP 27871 |
26.29 |
| 2026-06-04 12:00 |
05:54:17.24 |
+50:17:47.1 |
HIP 27871 |
26.63 |
| 2026-06-05 00:00 |
05:54:25.80 |
+50:17:37.1 |
HIP 27871 |
27.03 |
| 2026-06-05 12:00 |
05:54:34.38 |
+50:17:27.4 |
HIP 27871 |
27.49 |
| 2026-06-06 00:00 |
05:54:42.97 |
+50:17:17.9 |
HIP 27871 |
28.01 |
| 2026-06-06 12:00 |
05:54:51.58 |
+50:17:08.7 |
HIP 27871 |
28.58 |
| 2026-06-07 00:00 |
05:55:00.19 |
+50:16:59.7 |
HIP 27871 |
29.20 |
| 2026-06-07 12:00 |
05:55:08.82 |
+50:16:51.0 |
HIP 27871 |
29.87 |
| 2026-06-08 00:00 |
05:55:17.45 |
+50:16:42.5 |
HIP 27871 |
30.58 |
| 2026-06-08 12:00 |
05:55:26.10 |
+50:16:34.3 |
HIP 27871 |
31.34 |
| 2026-06-09 00:00 |
05:55:34.76 |
+50:16:26.3 |
HIP 27871 |
32.13 |
| 2026-06-09 12:00 |
05:55:43.43 |
+50:16:18.6 |
HIP 27871 |
32.96 |
| 2026-06-10 00:00 |
05:55:52.10 |
+50:16:11.1 |
HIP 27871 |
33.83 |
| 2026-06-10 12:00 |
05:56:00.79 |
+50:16:03.9 |
HIP 27871 |
34.72 |
| 2026-06-11 00:00 |
05:56:09.48 |
+50:15:56.9 |
HIP 27871 |
35.65 |
| 2026-06-11 12:00 |
05:56:18.18 |
+50:15:50.2 |
HIP 28343 |
35.80 |
| 2026-06-12 00:00 |
05:56:26.89 |
+50:15:43.8 |
HIP 28343 |
34.60 |
| 2026-06-12 12:00 |
05:56:35.61 |
+50:15:37.5 |
HIP 28343 |
33.41 |
| 2026-06-13 00:00 |
05:56:44.33 |
+50:15:31.6 |
HIP 28343 |
32.25 |
| 2026-06-13 12:00 |
05:56:53.06 |
+50:15:25.9 |
HIP 28343 |
31.10 |
| 2026-06-14 00:00 |
05:57:01.79 |
+50:15:20.4 |
HIP 28343 |
29.98 |
| 2026-06-14 12:00 |
05:57:10.53 |
+50:15:15.2 |
HIP 28343 |
28.89 |
| 2026-06-15 00:00 |
05:57:19.27 |
+50:15:10.3 |
HIP 28343 |
27.82 |
| 2026-06-15 12:00 |
05:57:28.02 |
+50:15:05.6 |
HIP 28343 |
26.79 |
| 2026-06-16 00:00 |
05:57:36.77 |
+50:15:01.1 |
HIP 28343 |
25.80 |
| 2026-06-16 12:00 |
05:57:45.52 |
+50:14:56.9 |
HIP 28343 |
24.85 |
| 2026-06-17 00:00 |
05:57:54.28 |
+50:14:53.0 |
HIP 28343 |
23.95 |
| 2026-06-17 12:00 |
05:58:03.04 |
+50:14:49.3 |
HIP 28343 |
23.11 |
| 2026-06-18 00:00 |
05:58:11.80 |
+50:14:45.9 |
HIP 28343 |
22.32 |
| 2026-06-18 12:00 |
05:58:20.56 |
+50:14:42.7 |
HIP 28343 |
21.60 |
| 2026-06-19 00:00 |
05:58:29.32 |
+50:14:39.8 |
HIP 28343 |
20.95 |
| 2026-06-19 12:00 |
05:58:38.08 |
+50:14:37.1 |
HIP 28343 |
20.39 |
| 2026-06-20 00:00 |
05:58:46.84 |
+50:14:34.7 |
HIP 28343 |
19.91 |
| 2026-06-20 12:00 |
05:58:55.59 |
+50:14:32.5 |
HIP 28343 |
19.53 |
| 2026-06-21 00:00 |
05:59:04.35 |
+50:14:30.6 |
HIP 28343 |
19.24 |
| 2026-06-21 12:00 |
05:59:13.11 |
+50:14:28.9 |
HIP 28343 |
19.06 |
| 2026-06-22 00:00 |
05:59:21.86 |
+50:14:27.5 |
HIP 28343 |
18.99 |