메타데이터
| 항목 |
값 |
| Designation |
C/2018 F1 (Grauer) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2018-12-14T01:55:08.552640Z |
| Orbit solution date (soln_date, UTC) |
2021-09-04T23:42:57Z |
| Obs used |
221 |
| NEO |
- |
| M1 |
12.700 |
| K1 |
6.250 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2018-03-17T08:17:23.424000Z |
| Discovery magnitude (MPC) |
19.10 T |
| Discovery observatory (MPC) |
G96 · Mt. Lemmon Survey |
Osculating 궤도요소
| 항목 |
값 |
| Epoch (epoch_cal, TDB) |
2019-03-06.0000000 |
| e |
0.99071069 |
| q (au) |
2.993048 |
| a (au) |
322.203595 |
| i (deg) |
46.070619 |
| Ω (om, deg) |
177.285875 |
| ω (w, deg) |
71.628120 |
| M (ma, deg) |
0.013960 |
밝기
산란 + 전체 선형
$$
M_a = (10.042 + 4.054\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
모델 상수
| 항목 |
값 |
| H0 |
10.042 |
| n |
4.054 |
| gf |
0.800 |
| gb |
-0.500 |
| k |
1.000 |
| δ90 |
1.000 |
| 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 |
| 2017-12-22 |
2018-07-16 |
+4.3609 |
-2.361 |
| 2019-03-22 |
2019-08-08 |
-24.0881 |
+12.948 |
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 |
01:19:18.17 |
-09:41:44.9 |
HIP 6237 |
15.77 |
| 2026-03-26 12:00 |
01:19:24.48 |
-09:41:09.8 |
HIP 6237 |
15.18 |
| 2026-03-27 00:00 |
01:19:30.80 |
-09:40:34.8 |
HIP 6237 |
14.75 |
| 2026-03-27 12:00 |
01:19:37.13 |
-09:40:00.1 |
HIP 6237 |
14.49 |
| 2026-03-28 00:00 |
01:19:43.47 |
-09:39:25.5 |
HIP 6237 |
14.42 |
| 2026-03-28 12:00 |
01:19:49.82 |
-09:38:51.0 |
HIP 6237 |
14.53 |
| 2026-03-29 00:00 |
01:19:56.18 |
-09:38:16.8 |
HIP 6237 |
14.83 |
| 2026-03-29 12:00 |
01:20:02.55 |
-09:37:42.7 |
HIP 6237 |
15.30 |
| 2026-03-30 00:00 |
01:20:08.92 |
-09:37:08.8 |
HIP 6237 |
15.94 |
| 2026-03-30 12:00 |
01:20:15.30 |
-09:36:35.1 |
HIP 6237 |
16.71 |
| 2026-03-31 00:00 |
01:20:21.70 |
-09:36:01.6 |
HIP 6237 |
17.61 |
| 2026-03-31 12:00 |
01:20:28.09 |
-09:35:28.2 |
HIP 6237 |
18.61 |
| 2026-04-01 00:00 |
01:20:34.50 |
-09:34:55.1 |
HIP 6237 |
19.70 |
| 2026-04-01 12:00 |
01:20:40.91 |
-09:34:22.1 |
HIP 6237 |
20.86 |
| 2026-04-02 00:00 |
01:20:47.33 |
-09:33:49.3 |
HIP 6237 |
22.09 |
| 2026-04-02 12:00 |
01:20:53.76 |
-09:33:16.8 |
HIP 6237 |
23.37 |
| 2026-04-03 00:00 |
01:21:00.19 |
-09:32:44.4 |
HIP 6237 |
24.70 |
| 2026-04-03 12:00 |
01:21:06.62 |
-09:32:12.2 |
HIP 6237 |
26.06 |
| 2026-04-04 00:00 |
01:21:13.06 |
-09:31:40.2 |
HIP 6237 |
27.46 |
| 2026-04-04 12:00 |
01:21:19.51 |
-09:31:08.4 |
HIP 6237 |
28.88 |
| 2026-04-05 00:00 |
01:21:25.96 |
-09:30:36.9 |
HIP 6237 |
30.33 |
| 2026-04-05 12:00 |
01:21:32.42 |
-09:30:05.5 |
HIP 6237 |
31.80 |
| 2026-04-06 00:00 |
01:21:38.87 |
-09:29:34.3 |
HIP 6237 |
33.29 |
| 2026-04-06 12:00 |
01:21:45.34 |
-09:29:03.4 |
HIP 6237 |
34.79 |
| 2026-04-07 00:00 |
01:21:51.80 |
-09:28:32.7 |
HIP 6237 |
36.31 |
| 2026-04-07 12:00 |
01:21:58.27 |
-09:28:02.1 |
HIP 6541 |
37.13 |
| 2026-04-08 00:00 |
01:22:04.74 |
-09:27:31.8 |
HIP 6541 |
36.11 |
| 2026-04-08 12:00 |
01:22:11.21 |
-09:27:01.8 |
HIP 6541 |
35.14 |
| 2026-04-09 00:00 |
01:22:17.69 |
-09:26:31.9 |
HIP 6541 |
34.22 |
| 2026-04-09 12:00 |
01:22:24.16 |
-09:26:02.3 |
HIP 6541 |
33.35 |
| 2026-04-10 00:00 |
01:22:30.64 |
-09:25:32.8 |
HIP 6541 |
32.55 |
| 2026-04-10 12:00 |
01:22:37.12 |
-09:25:03.7 |
HIP 6541 |
31.81 |
| 2026-04-11 00:00 |
01:22:43.59 |
-09:24:34.7 |
HIP 6541 |
31.14 |
| 2026-04-11 12:00 |
01:22:50.07 |
-09:24:06.0 |
HIP 6541 |
30.54 |
| 2026-04-12 00:00 |
01:22:56.55 |
-09:23:37.5 |
HIP 6541 |
30.02 |
| 2026-04-12 12:00 |
01:23:03.03 |
-09:23:09.2 |
HIP 6541 |
29.58 |
| 2026-04-13 00:00 |
01:23:09.50 |
-09:22:41.2 |
HIP 6541 |
29.22 |
| 2026-04-13 12:00 |
01:23:15.98 |
-09:22:13.5 |
HIP 6541 |
28.96 |
| 2026-04-14 00:00 |
01:23:22.45 |
-09:21:45.9 |
HIP 6541 |
28.78 |
| 2026-04-14 12:00 |
01:23:28.92 |
-09:21:18.6 |
HIP 6541 |
28.70 |
| 2026-04-15 00:00 |
01:23:35.39 |
-09:20:51.6 |
HIP 6541 |
28.70 |
| 2026-04-15 12:00 |
01:23:41.86 |
-09:20:24.8 |
HIP 6541 |
28.80 |
| 2026-04-16 00:00 |
01:23:48.32 |
-09:19:58.3 |
HIP 6541 |
28.99 |