메타데이터
| 항목 |
값 |
| Designation |
C/2018 Y1 (Iwamoto) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2019-02-07T00:44:05.775360Z |
| Orbit solution date (soln_date, UTC) |
2024-01-04T23:42:43Z |
| Obs used |
2771 |
| NEO |
- |
| M1 |
13.600 |
| K1 |
5.250 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2018-12-18T20:11:02.400000Z |
| Discovery magnitude (MPC) |
12.00 R |
| Discovery observatory (MPC) |
872 · Tokushima |
Osculating 궤도요소
| 항목 |
값 |
| Epoch (epoch_cal, TDB) |
2019-03-03.0000000 |
| e |
0.99107927 |
| q (au) |
1.286994 |
| a (au) |
144.270155 |
| i (deg) |
160.403537 |
| Ω (om, deg) |
147.483562 |
| ω (w, deg) |
358.057218 |
| M (ma, deg) |
0.013633 |
밝기
산란 + 전체 선형
$$
M_a = (13.253 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
모델 상수
| 항목 |
값 |
| H0 |
13.253 |
| n |
2.000 |
| gf |
0.972 |
| gb |
-0.632 |
| k |
0.984 |
| δ90 |
9.902 |
| 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 |
| 2018-12-18 |
2019-02-07 |
+11.1321 |
-3.457 |
| 2019-02-07 |
2019-12-22 |
+2.9643 |
-1.536 |
log10 r = log10(태양거리/AU), Δ = 지구거리(AU)
천체력
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
23:39:17.87 |
+08:45:02.5 |
HIP 116651 |
14.86 |
| 2026-07-29 12:00 |
23:39:13.69 |
+08:44:46.6 |
HIP 116651 |
13.80 |
| 2026-07-30 00:00 |
23:39:09.47 |
+08:44:30.3 |
HIP 116651 |
12.73 |
| 2026-07-30 12:00 |
23:39:05.21 |
+08:44:13.6 |
HIP 116651 |
11.66 |
| 2026-07-31 00:00 |
23:39:00.92 |
+08:43:56.7 |
HIP 116651 |
10.58 |
| 2026-07-31 12:00 |
23:38:56.59 |
+08:43:39.4 |
HIP 116651 |
9.49 |
| 2026-08-01 00:00 |
23:38:52.22 |
+08:43:21.8 |
HIP 116651 |
8.40 |
| 2026-08-01 12:00 |
23:38:47.82 |
+08:43:03.9 |
HIP 116651 |
7.30 |
| 2026-08-02 00:00 |
23:38:43.39 |
+08:42:45.6 |
HIP 116651 |
6.20 |
| 2026-08-02 12:00 |
23:38:38.92 |
+08:42:27.1 |
HIP 116651 |
5.12 |
| 2026-08-03 00:00 |
23:38:34.41 |
+08:42:08.2 |
HIP 116651 |
4.05 |
| 2026-08-03 12:00 |
23:38:29.87 |
+08:41:48.9 |
HIP 116651 |
3.04 |
| 2026-08-04 00:00 |
23:38:25.30 |
+08:41:29.4 |
HIP 116651 |
2.19 |
| 2026-08-04 12:00 |
23:38:20.69 |
+08:41:09.5 |
HIP 116651 |
1.77 |
| 2026-08-05 00:00 |
23:38:16.04 |
+08:40:49.3 |
HIP 116651 |
2.06 |
| 2026-08-05 12:00 |
23:38:11.37 |
+08:40:28.8 |
HIP 116651 |
2.87 |
| 2026-08-06 00:00 |
23:38:06.66 |
+08:40:08.0 |
HIP 116651 |
3.90 |
| 2026-08-06 12:00 |
23:38:01.92 |
+08:39:46.8 |
HIP 116651 |
5.03 |
| 2026-08-07 00:00 |
23:37:57.14 |
+08:39:25.4 |
HIP 116651 |
6.19 |
| 2026-08-07 12:00 |
23:37:52.33 |
+08:39:03.6 |
HIP 116651 |
7.39 |
| 2026-08-08 00:00 |
23:37:47.49 |
+08:38:41.5 |
HIP 116651 |
8.61 |
| 2026-08-08 12:00 |
23:37:42.62 |
+08:38:19.1 |
HIP 116651 |
9.84 |
| 2026-08-09 00:00 |
23:37:37.72 |
+08:37:56.3 |
HIP 116651 |
11.09 |
| 2026-08-09 12:00 |
23:37:32.79 |
+08:37:33.3 |
HIP 116651 |
12.36 |
| 2026-08-10 00:00 |
23:37:27.82 |
+08:37:09.9 |
HIP 116651 |
13.63 |
| 2026-08-10 12:00 |
23:37:22.83 |
+08:36:46.2 |
HIP 116651 |
14.91 |
| 2026-08-11 00:00 |
23:37:17.81 |
+08:36:22.2 |
HIP 116651 |
16.21 |
| 2026-08-11 12:00 |
23:37:12.75 |
+08:35:57.9 |
HIP 116651 |
17.51 |
| 2026-08-12 00:00 |
23:37:07.67 |
+08:35:33.3 |
HIP 116651 |
18.83 |
| 2026-08-12 12:00 |
23:37:02.56 |
+08:35:08.4 |
HIP 116651 |
20.15 |
| 2026-08-13 00:00 |
23:36:57.42 |
+08:34:43.2 |
HIP 116651 |
21.48 |
| 2026-08-13 12:00 |
23:36:52.25 |
+08:34:17.7 |
HIP 116417 |
21.35 |
| 2026-08-14 00:00 |
23:36:47.05 |
+08:33:51.9 |
HIP 116417 |
20.01 |
| 2026-08-14 12:00 |
23:36:41.83 |
+08:33:25.7 |
HIP 116417 |
18.68 |
| 2026-08-15 00:00 |
23:36:36.58 |
+08:32:59.3 |
HIP 116417 |
17.34 |
| 2026-08-15 12:00 |
23:36:31.30 |
+08:32:32.6 |
HIP 116417 |
16.00 |
| 2026-08-16 00:00 |
23:36:26.00 |
+08:32:05.6 |
HIP 116417 |
14.66 |
| 2026-08-16 12:00 |
23:36:20.67 |
+08:31:38.3 |
HIP 116417 |
13.32 |
| 2026-08-17 00:00 |
23:36:15.32 |
+08:31:10.7 |
HIP 116417 |
11.99 |
| 2026-08-17 12:00 |
23:36:09.94 |
+08:30:42.8 |
HIP 116417 |
10.67 |
| 2026-08-18 00:00 |
23:36:04.54 |
+08:30:14.6 |
HIP 116417 |
9.37 |
| 2026-08-18 12:00 |
23:35:59.11 |
+08:29:46.2 |
HIP 116417 |
8.11 |
| 2026-08-19 00:00 |
23:35:53.66 |
+08:29:17.4 |
HIP 116417 |
6.90 |