메타데이터
| 항목 |
값 |
| Designation |
C/2018 C2 (Lemmon) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2018-06-02T05:22:27.024960Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:41Z |
| Obs used |
1672 |
| NEO |
- |
| M1 |
7.600 |
| K1 |
26.500 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2018-02-05T13:13:03.072000Z |
| Discovery magnitude (MPC) |
19.60 G |
| Discovery observatory (MPC) |
G96 · University of Arizona Mt. Lemmon Survey |
Osculating 궤도요소
| 항목 |
값 |
| Epoch (epoch_cal, TDB) |
2018-05-20.0000000 |
| e |
1.00180656 |
| q (au) |
1.956513 |
| a (au) |
-1083.006061 |
| i (deg) |
34.453393 |
| Ω (om, deg) |
91.139716 |
| ω (w, deg) |
134.138488 |
| M (ma, deg) |
-0.000366 |
밝기
산란 + 전체 선형
$$
M_a = (10.243 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
모델 상수
| 항목 |
값 |
| H0 |
10.243 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.500 |
| 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 |
| 2018-01-28 |
2018-06-01 |
+12.3467 |
-3.481 |
| 2018-06-02 |
2018-10-27 |
-13.9723 |
+3.855 |
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 |
01:45:34.88 |
-27:33:44.7 |
HIP 8233 |
14.07 |
| 2026-09-20 12:00 |
01:45:30.13 |
-27:34:28.0 |
HIP 8233 |
15.18 |
| 2026-09-21 00:00 |
01:45:25.34 |
-27:35:10.9 |
HIP 8233 |
16.31 |
| 2026-09-21 12:00 |
01:45:20.53 |
-27:35:53.6 |
HIP 8233 |
17.45 |
| 2026-09-22 00:00 |
01:45:15.69 |
-27:36:35.9 |
HIP 8233 |
18.62 |
| 2026-09-22 12:00 |
01:45:10.83 |
-27:37:17.9 |
HIP 8233 |
19.80 |
| 2026-09-23 00:00 |
01:45:05.94 |
-27:37:59.6 |
HIP 8233 |
20.99 |
| 2026-09-23 12:00 |
01:45:01.02 |
-27:38:41.0 |
HIP 8233 |
22.19 |
| 2026-09-24 00:00 |
01:44:56.08 |
-27:39:22.1 |
HIP 8191 |
22.22 |
| 2026-09-24 12:00 |
01:44:51.12 |
-27:40:02.8 |
HIP 8191 |
21.85 |
| 2026-09-25 00:00 |
01:44:46.13 |
-27:40:43.2 |
HIP 8191 |
21.56 |
| 2026-09-25 12:00 |
01:44:41.11 |
-27:41:23.3 |
HIP 8191 |
21.35 |
| 2026-09-26 00:00 |
01:44:36.08 |
-27:42:03.0 |
HIP 8191 |
21.22 |
| 2026-09-26 12:00 |
01:44:31.02 |
-27:42:42.4 |
HIP 8191 |
21.18 |
| 2026-09-27 00:00 |
01:44:25.94 |
-27:43:21.4 |
HIP 8191 |
21.23 |
| 2026-09-27 12:00 |
01:44:20.84 |
-27:44:00.1 |
HIP 8191 |
21.36 |
| 2026-09-28 00:00 |
01:44:15.72 |
-27:44:38.4 |
HIP 8191 |
21.58 |
| 2026-09-28 12:00 |
01:44:10.57 |
-27:45:16.4 |
HIP 8191 |
21.88 |
| 2026-09-29 00:00 |
01:44:05.41 |
-27:45:54.0 |
HIP 8191 |
22.26 |
| 2026-09-29 12:00 |
01:44:00.22 |
-27:46:31.3 |
HIP 8191 |
22.71 |
| 2026-09-30 00:00 |
01:43:55.02 |
-27:47:08.2 |
HIP 8191 |
23.24 |
| 2026-09-30 12:00 |
01:43:49.80 |
-27:47:44.7 |
HIP 8191 |
23.83 |
| 2026-10-01 00:00 |
01:43:44.55 |
-27:48:20.8 |
HIP 8191 |
24.49 |
| 2026-10-01 12:00 |
01:43:39.29 |
-27:48:56.6 |
HIP 8191 |
25.20 |
| 2026-10-02 00:00 |
01:43:34.02 |
-27:49:32.0 |
HIP 7947 |
25.35 |
| 2026-10-02 12:00 |
01:43:28.72 |
-27:50:07.0 |
HIP 7917 |
24.20 |
| 2026-10-03 00:00 |
01:43:23.41 |
-27:50:41.6 |
HIP 7917 |
22.90 |
| 2026-10-03 12:00 |
01:43:18.08 |
-27:51:15.8 |
HIP 7917 |
21.60 |
| 2026-10-04 00:00 |
01:43:12.73 |
-27:51:49.7 |
HIP 7917 |
20.30 |
| 2026-10-04 12:00 |
01:43:07.37 |
-27:52:23.1 |
HIP 7917 |
19.00 |
| 2026-10-05 00:00 |
01:43:01.99 |
-27:52:56.1 |
HIP 7917 |
17.70 |
| 2026-10-05 12:00 |
01:42:56.60 |
-27:53:28.7 |
HIP 7917 |
16.40 |
| 2026-10-06 00:00 |
01:42:51.20 |
-27:54:01.0 |
HIP 7917 |
15.10 |
| 2026-10-06 12:00 |
01:42:45.78 |
-27:54:32.8 |
HIP 7917 |
13.80 |
| 2026-10-07 00:00 |
01:42:40.35 |
-27:55:04.1 |
HIP 7917 |
12.51 |
| 2026-10-07 12:00 |
01:42:34.90 |
-27:55:35.1 |
HIP 7917 |
11.22 |
| 2026-10-08 00:00 |
01:42:29.45 |
-27:56:05.6 |
HIP 7917 |
9.93 |
| 2026-10-08 12:00 |
01:42:23.98 |
-27:56:35.8 |
HIP 7917 |
8.64 |
| 2026-10-09 00:00 |
01:42:18.50 |
-27:57:05.4 |
HIP 7917 |
7.36 |
| 2026-10-09 12:00 |
01:42:13.01 |
-27:57:34.7 |
HIP 7917 |
6.10 |
| 2026-10-10 00:00 |
01:42:07.51 |
-27:58:03.5 |
HIP 7917 |
4.85 |
| 2026-10-10 12:00 |
01:42:02.01 |
-27:58:31.9 |
HIP 7917 |
3.64 |
| 2026-10-11 00:00 |
01:41:56.49 |
-27:58:59.8 |
HIP 7917 |
2.52 |