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 · 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 |
-0.998 |
| 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) |
| 2026-03-26 00:00 |
01:32:34.74 |
-25:41:54.0 |
HIP 7236 |
9.45 |
| 2026-03-26 12:00 |
01:32:40.69 |
-25:41:09.9 |
HIP 7236 |
8.00 |
| 2026-03-27 00:00 |
01:32:46.65 |
-25:40:26.0 |
HIP 7236 |
6.59 |
| 2026-03-27 12:00 |
01:32:52.63 |
-25:39:42.5 |
HIP 7236 |
5.24 |
| 2026-03-28 00:00 |
01:32:58.61 |
-25:38:59.3 |
HIP 7236 |
4.02 |
| 2026-03-28 12:00 |
01:33:04.62 |
-25:38:16.4 |
HIP 7236 |
3.08 |
| 2026-03-29 00:00 |
01:33:10.63 |
-25:37:33.8 |
HIP 7236 |
2.73 |
| 2026-03-29 12:00 |
01:33:16.65 |
-25:36:51.6 |
HIP 7236 |
3.17 |
| 2026-03-30 00:00 |
01:33:22.69 |
-25:36:09.7 |
HIP 7236 |
4.16 |
| 2026-03-30 12:00 |
01:33:28.73 |
-25:35:28.2 |
HIP 7236 |
5.41 |
| 2026-03-31 00:00 |
01:33:34.79 |
-25:34:47.0 |
HIP 7236 |
6.76 |
| 2026-03-31 12:00 |
01:33:40.86 |
-25:34:06.1 |
HIP 7236 |
8.18 |
| 2026-04-01 00:00 |
01:33:46.93 |
-25:33:25.6 |
HIP 7236 |
9.63 |
| 2026-04-01 12:00 |
01:33:53.02 |
-25:32:45.4 |
HIP 7236 |
11.10 |
| 2026-04-02 00:00 |
01:33:59.11 |
-25:32:05.5 |
HIP 7236 |
12.58 |
| 2026-04-02 12:00 |
01:34:05.22 |
-25:31:26.0 |
HIP 7236 |
14.06 |
| 2026-04-03 00:00 |
01:34:11.33 |
-25:30:46.9 |
HIP 7236 |
15.56 |
| 2026-04-03 12:00 |
01:34:17.45 |
-25:30:08.1 |
HIP 7408 |
16.71 |
| 2026-04-04 00:00 |
01:34:23.58 |
-25:29:29.6 |
HIP 7408 |
15.21 |
| 2026-04-04 12:00 |
01:34:29.72 |
-25:28:51.5 |
HIP 7408 |
13.72 |
| 2026-04-05 00:00 |
01:34:35.86 |
-25:28:13.8 |
HIP 7408 |
12.24 |
| 2026-04-05 12:00 |
01:34:42.01 |
-25:27:36.4 |
HIP 7408 |
10.76 |
| 2026-04-06 00:00 |
01:34:48.17 |
-25:26:59.4 |
HIP 7408 |
9.30 |
| 2026-04-06 12:00 |
01:34:54.33 |
-25:26:22.8 |
HIP 7408 |
7.87 |
| 2026-04-07 00:00 |
01:35:00.50 |
-25:25:46.5 |
HIP 7408 |
6.46 |
| 2026-04-07 12:00 |
01:35:06.67 |
-25:25:10.5 |
HIP 7408 |
5.13 |
| 2026-04-08 00:00 |
01:35:12.85 |
-25:24:35.0 |
HIP 7408 |
3.92 |
| 2026-04-08 12:00 |
01:35:19.04 |
-25:23:59.8 |
HIP 7408 |
3.00 |
| 2026-04-09 00:00 |
01:35:25.23 |
-25:23:25.0 |
HIP 7408 |
2.69 |
| 2026-04-09 12:00 |
01:35:31.42 |
-25:22:50.5 |
HIP 7408 |
3.16 |
| 2026-04-10 00:00 |
01:35:37.62 |
-25:22:16.4 |
HIP 7408 |
4.15 |
| 2026-04-10 12:00 |
01:35:43.82 |
-25:21:42.7 |
HIP 7408 |
5.39 |
| 2026-04-11 00:00 |
01:35:50.02 |
-25:21:09.4 |
HIP 7408 |
6.73 |
| 2026-04-11 12:00 |
01:35:56.23 |
-25:20:36.5 |
HIP 7408 |
8.13 |
| 2026-04-12 00:00 |
01:36:02.44 |
-25:20:03.9 |
HIP 7408 |
9.56 |
| 2026-04-12 12:00 |
01:36:08.65 |
-25:19:31.8 |
HIP 7408 |
11.00 |
| 2026-04-13 00:00 |
01:36:14.86 |
-25:19:00.0 |
HIP 7408 |
12.46 |
| 2026-04-13 12:00 |
01:36:21.08 |
-25:18:28.6 |
HIP 7408 |
13.92 |
| 2026-04-14 00:00 |
01:36:27.29 |
-25:17:57.6 |
HIP 7408 |
15.38 |
| 2026-04-14 12:00 |
01:36:33.51 |
-25:17:26.9 |
HIP 7408 |
16.85 |
| 2026-04-15 00:00 |
01:36:39.72 |
-25:16:56.7 |
HIP 7541 |
17.41 |
| 2026-04-15 12:00 |
01:36:45.94 |
-25:16:26.9 |
HIP 7541 |
16.44 |
| 2026-04-16 00:00 |
01:36:52.15 |
-25:15:57.5 |
HIP 7541 |
15.56 |