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) |
| 2026-09-20 00:00 |
23:29:35.84 |
+07:50:25.3 |
HIP 116058 |
21.38 |
| 2026-09-20 12:00 |
23:29:29.81 |
+07:49:43.0 |
HIP 116058 |
22.60 |
| 2026-09-21 00:00 |
23:29:23.79 |
+07:49:00.6 |
HIP 116058 |
23.88 |
| 2026-09-21 12:00 |
23:29:17.78 |
+07:48:18.1 |
HIP 116058 |
25.19 |
| 2026-09-22 00:00 |
23:29:11.78 |
+07:47:35.5 |
HIP 115883 |
26.54 |
| 2026-09-22 12:00 |
23:29:05.78 |
+07:46:52.8 |
HIP 115883 |
25.48 |
| 2026-09-23 00:00 |
23:28:59.80 |
+07:46:09.9 |
HIP 115883 |
24.48 |
| 2026-09-23 12:00 |
23:28:53.82 |
+07:45:27.0 |
HIP 115883 |
23.55 |
| 2026-09-24 00:00 |
23:28:47.85 |
+07:44:44.0 |
HIP 115883 |
22.71 |
| 2026-09-24 12:00 |
23:28:41.89 |
+07:44:00.9 |
HIP 115883 |
21.95 |
| 2026-09-25 00:00 |
23:28:35.95 |
+07:43:17.7 |
HIP 115883 |
21.30 |
| 2026-09-25 12:00 |
23:28:30.01 |
+07:42:34.4 |
HIP 115883 |
20.75 |
| 2026-09-26 00:00 |
23:28:24.09 |
+07:41:51.1 |
HIP 115883 |
20.31 |
| 2026-09-26 12:00 |
23:28:18.18 |
+07:41:07.6 |
HIP 115883 |
20.00 |
| 2026-09-27 00:00 |
23:28:12.28 |
+07:40:24.1 |
HIP 115883 |
19.82 |
| 2026-09-27 12:00 |
23:28:06.39 |
+07:39:40.5 |
HIP 115883 |
19.76 |
| 2026-09-28 00:00 |
23:28:00.52 |
+07:38:56.9 |
HIP 115883 |
19.84 |
| 2026-09-28 12:00 |
23:27:54.66 |
+07:38:13.1 |
HIP 115883 |
20.05 |
| 2026-09-29 00:00 |
23:27:48.81 |
+07:37:29.4 |
HIP 115883 |
20.38 |
| 2026-09-29 12:00 |
23:27:42.98 |
+07:36:45.5 |
HIP 115883 |
20.83 |
| 2026-09-30 00:00 |
23:27:37.16 |
+07:36:01.6 |
HIP 115883 |
21.39 |
| 2026-09-30 12:00 |
23:27:31.36 |
+07:35:17.7 |
HIP 115883 |
22.06 |
| 2026-10-01 00:00 |
23:27:25.58 |
+07:34:33.7 |
HIP 115883 |
22.81 |
| 2026-10-01 12:00 |
23:27:19.81 |
+07:33:49.6 |
HIP 115883 |
23.64 |
| 2026-10-02 00:00 |
23:27:14.06 |
+07:33:05.5 |
HIP 115883 |
24.55 |
| 2026-10-02 12:00 |
23:27:08.33 |
+07:32:21.4 |
HIP 115883 |
25.53 |
| 2026-10-03 00:00 |
23:27:02.61 |
+07:31:37.2 |
HIP 115883 |
26.55 |
| 2026-10-03 12:00 |
23:26:56.92 |
+07:30:53.0 |
HIP 115883 |
27.63 |
| 2026-10-04 00:00 |
23:26:51.24 |
+07:30:08.8 |
HIP 115883 |
28.75 |
| 2026-10-04 12:00 |
23:26:45.58 |
+07:29:24.5 |
HIP 115883 |
29.91 |
| 2026-10-05 00:00 |
23:26:39.94 |
+07:28:40.3 |
HIP 115883 |
31.11 |
| 2026-10-05 12:00 |
23:26:34.32 |
+07:27:56.0 |
HIP 115883 |
32.33 |
| 2026-10-06 00:00 |
23:26:28.72 |
+07:27:11.6 |
HIP 115600 |
33.51 |
| 2026-10-06 12:00 |
23:26:23.14 |
+07:26:27.3 |
HIP 115600 |
32.05 |
| 2026-10-07 00:00 |
23:26:17.58 |
+07:25:43.0 |
HIP 115600 |
30.60 |
| 2026-10-07 12:00 |
23:26:12.05 |
+07:24:58.6 |
HIP 115600 |
29.17 |
| 2026-10-08 00:00 |
23:26:06.53 |
+07:24:14.3 |
HIP 115600 |
27.75 |
| 2026-10-08 12:00 |
23:26:01.04 |
+07:23:30.0 |
HIP 115600 |
26.36 |
| 2026-10-09 00:00 |
23:25:55.58 |
+07:22:45.6 |
HIP 115600 |
24.98 |
| 2026-10-09 12:00 |
23:25:50.14 |
+07:22:01.3 |
HIP 115600 |
23.63 |
| 2026-10-10 00:00 |
23:25:44.72 |
+07:21:17.0 |
HIP 115600 |
22.30 |
| 2026-10-10 12:00 |
23:25:39.32 |
+07:20:32.7 |
HIP 115600 |
21.01 |
| 2026-10-11 00:00 |
23:25:33.95 |
+07:19:48.4 |
HIP 115600 |
19.76 |