메타데이터
| 항목 |
값 |
| Designation |
C/2015 X7 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2016-07-30T05:59:33.682560Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:20Z |
| Obs used |
620 |
| NEO |
- |
| M1 |
11.600 |
| K1 |
6.000 |
| PC |
- |
Osculating 궤도요소
| 항목 |
값 |
| Epoch (epoch_cal, TDB) |
2016-09-22.0000000 |
| e |
1.00189036 |
| q (au) |
3.684550 |
| a (au) |
-1949.127032 |
| i (deg) |
57.578925 |
| Ω (om, deg) |
139.884070 |
| ω (w, deg) |
348.488537 |
| M (ma, deg) |
0.000616 |
밝기
산란 + 전체 선형
$$
M_a = (11.078 + 2.092\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
모델 상수
| 항목 |
값 |
| H0 |
11.078 |
| n |
2.092 |
| 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 |
| 2015-01-28 |
2016-05-01 |
-0.2726 |
-0.309 |
| 2016-11-02 |
2017-06-16 |
-0.5340 |
+0.555 |
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 |
18:15:17.12 |
+22:59:11.9 |
HIP 89495 |
19.85 |
| 2026-09-20 12:00 |
18:15:17.17 |
+22:58:11.5 |
HIP 89495 |
18.91 |
| 2026-09-21 00:00 |
18:15:17.27 |
+22:57:11.0 |
HIP 89495 |
17.97 |
| 2026-09-21 12:00 |
18:15:17.42 |
+22:56:10.7 |
HIP 89495 |
17.04 |
| 2026-09-22 00:00 |
18:15:17.61 |
+22:55:10.3 |
HIP 89495 |
16.11 |
| 2026-09-22 12:00 |
18:15:17.85 |
+22:54:09.9 |
HIP 89495 |
15.19 |
| 2026-09-23 00:00 |
18:15:18.14 |
+22:53:09.6 |
HIP 89495 |
14.28 |
| 2026-09-23 12:00 |
18:15:18.47 |
+22:52:09.2 |
HIP 89495 |
13.37 |
| 2026-09-24 00:00 |
18:15:18.85 |
+22:51:08.9 |
HIP 89495 |
12.47 |
| 2026-09-24 12:00 |
18:15:19.28 |
+22:50:08.7 |
HIP 89495 |
11.59 |
| 2026-09-25 00:00 |
18:15:19.76 |
+22:49:08.5 |
HIP 89495 |
10.72 |
| 2026-09-25 12:00 |
18:15:20.28 |
+22:48:08.3 |
HIP 89495 |
9.87 |
| 2026-09-26 00:00 |
18:15:20.85 |
+22:47:08.1 |
HIP 89495 |
9.05 |
| 2026-09-26 12:00 |
18:15:21.46 |
+22:46:08.0 |
HIP 89495 |
8.26 |
| 2026-09-27 00:00 |
18:15:22.12 |
+22:45:08.0 |
HIP 89495 |
7.51 |
| 2026-09-27 12:00 |
18:15:22.83 |
+22:44:08.0 |
HIP 89495 |
6.83 |
| 2026-09-28 00:00 |
18:15:23.58 |
+22:43:08.1 |
HIP 89495 |
6.23 |
| 2026-09-28 12:00 |
18:15:24.38 |
+22:42:08.2 |
HIP 89495 |
5.74 |
| 2026-09-29 00:00 |
18:15:25.23 |
+22:41:08.4 |
HIP 89495 |
5.38 |
| 2026-09-29 12:00 |
18:15:26.12 |
+22:40:08.7 |
HIP 89495 |
5.19 |
| 2026-09-30 00:00 |
18:15:27.06 |
+22:39:09.0 |
HIP 89495 |
5.18 |
| 2026-09-30 12:00 |
18:15:28.04 |
+22:38:09.4 |
HIP 89495 |
5.36 |
| 2026-10-01 00:00 |
18:15:29.07 |
+22:37:09.9 |
HIP 89495 |
5.71 |
| 2026-10-01 12:00 |
18:15:30.15 |
+22:36:10.5 |
HIP 89495 |
6.20 |
| 2026-10-02 00:00 |
18:15:31.27 |
+22:35:11.1 |
HIP 89495 |
6.80 |
| 2026-10-02 12:00 |
18:15:32.44 |
+22:34:11.9 |
HIP 89495 |
7.49 |
| 2026-10-03 00:00 |
18:15:33.65 |
+22:33:12.7 |
HIP 89495 |
8.24 |
| 2026-10-03 12:00 |
18:15:34.91 |
+22:32:13.7 |
HIP 89495 |
9.04 |
| 2026-10-04 00:00 |
18:15:36.22 |
+22:31:14.7 |
HIP 89495 |
9.88 |
| 2026-10-04 12:00 |
18:15:37.57 |
+22:30:15.9 |
HIP 89495 |
10.75 |
| 2026-10-05 00:00 |
18:15:38.96 |
+22:29:17.1 |
HIP 89495 |
11.63 |
| 2026-10-05 12:00 |
18:15:40.41 |
+22:28:18.5 |
HIP 89495 |
12.54 |
| 2026-10-06 00:00 |
18:15:41.89 |
+22:27:20.0 |
HIP 89495 |
13.46 |
| 2026-10-06 12:00 |
18:15:43.43 |
+22:26:21.6 |
HIP 89495 |
14.40 |
| 2026-10-07 00:00 |
18:15:45.00 |
+22:25:23.3 |
HIP 89495 |
15.34 |
| 2026-10-07 12:00 |
18:15:46.63 |
+22:24:25.2 |
HIP 89495 |
16.30 |
| 2026-10-08 00:00 |
18:15:48.30 |
+22:23:27.2 |
HIP 89495 |
17.26 |
| 2026-10-08 12:00 |
18:15:50.01 |
+22:22:29.4 |
HIP 89495 |
18.22 |
| 2026-10-09 00:00 |
18:15:51.77 |
+22:21:31.7 |
HIP 89484 |
18.72 |
| 2026-10-09 12:00 |
18:15:53.57 |
+22:20:34.1 |
HIP 89484 |
17.84 |
| 2026-10-10 00:00 |
18:15:55.42 |
+22:19:36.7 |
HIP 89484 |
16.99 |
| 2026-10-10 12:00 |
18:15:57.31 |
+22:18:39.4 |
HIP 89484 |
16.17 |
| 2026-10-11 00:00 |
18:15:59.24 |
+22:17:42.3 |
HIP 89484 |
15.38 |