C/2021 T4 (Lemmon)
메타데이터
| 항목 | 값 |
|---|---|
| Designation | C/2021 T4 (Lemmon) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2023-07-31T12:38:55.115520Z |
| Orbit solution date (soln_date, UTC) | 2025-04-14T09:29:19Z |
| Obs used | 1259 |
| NEO | - |
| M1 | 12.400 |
| K1 | 4.500 |
| PC | - |
| Discovery observation (MPC, UTC) | 2021-10-07T08:22:46.128000Z |
| Discovery magnitude (MPC) | 20.27 G |
| Discovery observatory (MPC) | G96 · Mt. Lemmon Survey |
Osculating 궤도요소
| 항목 | 값 |
|---|---|
| Epoch (epoch_cal, TDB) | 2023-04-14.0000000 |
| e | 0.99991819 |
| q (au) | 1.483298 |
| a (au) | 18131.786728 |
| i (deg) | 160.777409 |
| Ω (om, deg) | 257.882312 |
| ω (w, deg) | 329.813930 |
| M (ma, deg) | 359.999956 |
밝기
산란 + 전체 선형
$$ M_a = (12.728 + 3.054\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
모델 상수
| 항목 | 값 |
|---|---|
| H0 | 12.728 |
| n | 3.054 |
| gf | 1.000 |
| gb | -0.748 |
| k | 0.800 |
| 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 |
|---|---|---|---|
| 2021-08-07 | 2023-07-28 | +2.7531 | -2.268 |
| 2023-07-31 | 2024-04-13 | +9.0393 | -3.499 |
| 2024-04-13 | 2025-03-24 | -0.2550 | +1.251 |
log10 r = log10(태양거리/AU), Δ = 지구거리(AU)
찾아보기
천체력
| Date/Time (UTC) | RA (J2000) | Dec (J2000) | Nearest HIP | Dist from HIP (arcmin) |
|---|---|---|---|---|
| 2026-02-03 00:00 | 11:11:13.23 | +27:53:48.7 | HIP 54492 | 30.71 |
| 2026-02-03 12:00 | 11:10:57.37 | +27:55:53.1 | HIP 54492 | 26.93 |
| 2026-02-04 00:00 | 11:10:41.44 | +27:57:57.1 | HIP 54492 | 23.24 |
| 2026-02-04 12:00 | 11:10:25.42 | +28:00:00.7 | HIP 54492 | 19.68 |
| 2026-02-05 00:00 | 11:10:09.33 | +28:02:04.0 | HIP 54492 | 16.35 |
| 2026-02-05 12:00 | 11:09:53.17 | +28:04:06.8 | HIP 54492 | 13.45 |
| 2026-02-06 00:00 | 11:09:36.93 | +28:06:09.2 | HIP 54484 | 10.68 |
| 2026-02-06 12:00 | 11:09:20.61 | +28:08:11.1 | HIP 54484 | 7.46 |
| 2026-02-07 00:00 | 11:09:04.23 | +28:10:12.6 | HIP 54484 | 5.58 |
| 2026-02-07 12:00 | 11:08:47.78 | +28:12:13.7 | HIP 54456 | 5.90 |
| 2026-02-08 00:00 | 11:08:31.25 | +28:14:14.3 | HIP 54456 | 2.46 |
| 2026-02-08 12:00 | 11:08:14.67 | +28:16:14.3 | HIP 54456 | 3.46 |
| 2026-02-09 00:00 | 11:07:58.01 | +28:18:13.9 | HIP 54456 | 7.26 |
| 2026-02-09 12:00 | 11:07:41.29 | +28:20:13.0 | HIP 54456 | 11.33 |
| 2026-02-10 00:00 | 11:07:24.51 | +28:22:11.5 | HIP 54456 | 15.47 |
| 2026-02-10 12:00 | 11:07:07.67 | +28:24:09.5 | HIP 54456 | 19.64 |
| 2026-02-11 00:00 | 11:06:50.77 | +28:26:06.9 | HIP 54456 | 23.83 |
| 2026-02-11 12:00 | 11:06:33.81 | +28:28:03.8 | HIP 54132 | 27.72 |
| 2026-02-12 00:00 | 11:06:16.80 | +28:30:00.1 | HIP 54132 | 23.75 |
| 2026-02-12 12:00 | 11:05:59.73 | +28:31:55.8 | HIP 54132 | 19.86 |
| 2026-02-13 00:00 | 11:05:42.60 | +28:33:50.9 | HIP 54132 | 16.13 |
| 2026-02-13 12:00 | 11:05:25.43 | +28:35:45.4 | HIP 54132 | 12.70 |
| 2026-02-14 00:00 | 11:05:08.20 | +28:37:39.2 | HIP 54132 | 9.89 |
| 2026-02-14 12:00 | 11:04:50.93 | +28:39:32.4 | HIP 54132 | 8.36 |
| 2026-02-15 00:00 | 11:04:33.61 | +28:41:25.0 | HIP 54132 | 8.81 |
| 2026-02-15 12:00 | 11:04:16.25 | +28:43:16.8 | HIP 54132 | 11.01 |
| 2026-02-16 00:00 | 11:03:58.84 | +28:45:08.0 | HIP 54132 | 14.16 |
| 2026-02-16 12:00 | 11:03:41.40 | +28:46:58.6 | HIP 54024 | 11.00 |
| 2026-02-17 00:00 | 11:03:23.91 | +28:48:48.4 | HIP 54024 | 7.51 |
| 2026-02-17 12:00 | 11:03:06.38 | +28:50:37.5 | HIP 54024 | 5.30 |
| 2026-02-18 00:00 | 11:02:48.82 | +28:52:25.9 | HIP 54024 | 6.00 |
| 2026-02-18 12:00 | 11:02:31.23 | +28:54:13.5 | HIP 54024 | 8.95 |
| 2026-02-19 00:00 | 11:02:13.60 | +28:56:00.4 | HIP 54024 | 12.67 |
| 2026-02-19 12:00 | 11:01:55.94 | +28:57:46.5 | HIP 54024 | 16.64 |
| 2026-02-20 00:00 | 11:01:38.25 | +28:59:31.9 | HIP 53833 | 17.37 |
| 2026-02-20 12:00 | 11:01:20.54 | +29:01:16.5 | HIP 53833 | 13.74 |
| 2026-02-21 00:00 | 11:01:02.80 | +29:03:00.3 | HIP 53833 | 10.57 |
| 2026-02-21 12:00 | 11:00:45.03 | +29:04:43.3 | HIP 53833 | 8.43 |
| 2026-02-22 00:00 | 11:00:27.25 | +29:06:25.5 | HIP 53833 | 8.16 |
| 2026-02-22 12:00 | 11:00:09.44 | +29:08:06.9 | HIP 53833 | 9.92 |
| 2026-02-23 00:00 | 10:59:51.62 | +29:09:47.4 | HIP 53833 | 12.89 |
| 2026-02-23 12:00 | 10:59:33.78 | +29:11:27.1 | HIP 53833 | 16.43 |
| 2026-02-24 00:00 | 10:59:15.93 | +29:13:06.0 | HIP 53833 | 20.24 |