메타데이터
| 항목 |
값 |
| Designation |
C/2017 K4 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2018-01-08T01:00:52.058880Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:33Z |
| Obs used |
556 |
| NEO |
- |
| M1 |
4.700 |
| K1 |
19.500 |
| PC |
0.030 |
Osculating 궤도요소
| 항목 |
값 |
| Epoch (epoch_cal, TDB) |
2018-03-28.0000000 |
| e |
0.90585450 |
| q (au) |
2.648085 |
| a (au) |
28.127579 |
| i (deg) |
16.678706 |
| Ω (om, deg) |
298.897270 |
| ω (w, deg) |
15.111911 |
| M (ma, deg) |
0.521675 |
밝기
산란 + 전체 선형
$$
M_a = (6.069 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
모델 상수
| 항목 |
값 |
| H0 |
6.069 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| 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 |
| 2016-05-06 |
2017-11-12 |
+3.1769 |
-1.847 |
| 2018-04-27 |
2019-01-27 |
-4.4170 |
+2.873 |
log10 r = log10(태양거리/AU), Δ = 지구거리(AU)
천체력
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
06:29:11.22 |
+28:59:59.3 |
HIP 30943 |
14.53 |
| 2026-05-12 12:00 |
06:29:16.83 |
+28:59:46.2 |
HIP 30943 |
13.85 |
| 2026-05-13 00:00 |
06:29:22.47 |
+28:59:33.2 |
HIP 30943 |
13.25 |
| 2026-05-13 12:00 |
06:29:28.15 |
+28:59:20.2 |
HIP 30943 |
12.74 |
| 2026-05-14 00:00 |
06:29:33.86 |
+28:59:07.2 |
HIP 30943 |
12.34 |
| 2026-05-14 12:00 |
06:29:39.61 |
+28:58:54.2 |
HIP 30943 |
12.06 |
| 2026-05-15 00:00 |
06:29:45.40 |
+28:58:41.3 |
HIP 30943 |
11.92 |
| 2026-05-15 12:00 |
06:29:51.22 |
+28:58:28.4 |
HIP 30943 |
11.91 |
| 2026-05-16 00:00 |
06:29:57.07 |
+28:58:15.5 |
HIP 30943 |
12.05 |
| 2026-05-16 12:00 |
06:30:02.96 |
+28:58:02.6 |
HIP 30943 |
12.33 |
| 2026-05-17 00:00 |
06:30:08.89 |
+28:57:49.8 |
HIP 30943 |
12.73 |
| 2026-05-17 12:00 |
06:30:14.84 |
+28:57:37.0 |
HIP 30943 |
13.27 |
| 2026-05-18 00:00 |
06:30:20.83 |
+28:57:24.2 |
HIP 30943 |
13.91 |
| 2026-05-18 12:00 |
06:30:26.86 |
+28:57:11.4 |
HIP 30943 |
14.65 |
| 2026-05-19 00:00 |
06:30:32.91 |
+28:56:58.7 |
HIP 30943 |
15.48 |
| 2026-05-19 12:00 |
06:30:39.00 |
+28:56:46.0 |
HIP 31117 |
14.81 |
| 2026-05-20 00:00 |
06:30:45.11 |
+28:56:33.3 |
HIP 31117 |
13.53 |
| 2026-05-20 12:00 |
06:30:51.26 |
+28:56:20.6 |
HIP 31117 |
12.26 |
| 2026-05-21 00:00 |
06:30:57.44 |
+28:56:08.0 |
HIP 31117 |
11.01 |
| 2026-05-21 12:00 |
06:31:03.65 |
+28:55:55.4 |
HIP 31117 |
9.78 |
| 2026-05-22 00:00 |
06:31:09.89 |
+28:55:42.8 |
HIP 31117 |
8.60 |
| 2026-05-22 12:00 |
06:31:16.16 |
+28:55:30.2 |
HIP 31117 |
7.47 |
| 2026-05-23 00:00 |
06:31:22.46 |
+28:55:17.7 |
HIP 31117 |
6.43 |
| 2026-05-23 12:00 |
06:31:28.78 |
+28:55:05.2 |
HIP 31117 |
5.56 |
| 2026-05-24 00:00 |
06:31:35.14 |
+28:54:52.8 |
HIP 31117 |
4.92 |
| 2026-05-24 12:00 |
06:31:41.52 |
+28:54:40.3 |
HIP 31117 |
4.64 |
| 2026-05-25 00:00 |
06:31:47.93 |
+28:54:27.9 |
HIP 31117 |
4.78 |
| 2026-05-25 12:00 |
06:31:54.36 |
+28:54:15.5 |
HIP 31117 |
5.31 |
| 2026-05-26 00:00 |
06:32:00.82 |
+28:54:03.2 |
HIP 31117 |
6.13 |
| 2026-05-26 12:00 |
06:32:07.31 |
+28:53:50.8 |
HIP 31117 |
7.15 |
| 2026-05-27 00:00 |
06:32:13.83 |
+28:53:38.5 |
HIP 31117 |
8.29 |
| 2026-05-27 12:00 |
06:32:20.37 |
+28:53:26.3 |
HIP 31117 |
9.53 |
| 2026-05-28 00:00 |
06:32:26.93 |
+28:53:14.0 |
HIP 31117 |
10.81 |
| 2026-05-28 12:00 |
06:32:33.52 |
+28:53:01.8 |
HIP 31117 |
12.14 |
| 2026-05-29 00:00 |
06:32:40.13 |
+28:52:49.7 |
HIP 31117 |
13.50 |
| 2026-05-29 12:00 |
06:32:46.77 |
+28:52:37.5 |
HIP 31117 |
14.89 |
| 2026-05-30 00:00 |
06:32:53.43 |
+28:52:25.4 |
HIP 31117 |
16.29 |
| 2026-05-30 12:00 |
06:33:00.11 |
+28:52:13.3 |
HIP 31117 |
17.71 |
| 2026-05-31 00:00 |
06:33:06.82 |
+28:52:01.3 |
HIP 31202 |
18.25 |
| 2026-05-31 12:00 |
06:33:13.55 |
+28:51:49.3 |
HIP 31202 |
18.86 |
| 2026-06-01 00:00 |
06:33:20.30 |
+28:51:37.3 |
HIP 31202 |
19.56 |
| 2026-06-01 12:00 |
06:33:27.08 |
+28:51:25.3 |
HIP 31202 |
20.35 |
| 2026-06-02 00:00 |
06:33:33.87 |
+28:51:13.4 |
HIP 31202 |
21.21 |