C/2022 T1 (Lemmon)
Metadata
| Parameter | Value |
|---|---|
| Designation | C/2022 T1 (Lemmon) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2024-02-17T12:18:13.901760Z |
| Orbit solution date (soln_date, UTC) | 2024-07-22T18:42:14Z |
| Obs used | 587 |
| NEO | - |
| M1 | 13.100 |
| K1 | 4.500 |
| PC | - |
| Discovery observation (MPC, UTC) | 2022-10-03T11:55:57.561600Z |
| Discovery magnitude (MPC) | 21.24 G |
| Discovery observatory (MPC) | G96 · Mt. Lemmon Survey |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2023-10-10.0000000 |
| e | 0.99971338 |
| q (au) | 3.444855 |
| a (au) | 12018.953434 |
| i (deg) | 22.543649 |
| Ω (om, deg) | 236.919592 |
| ω (w, deg) | 324.316453 |
| M (ma, deg) | 359.999902 |
Magnitude
Scatter + Global Linear
$$ M_a = (11.928 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 11.928 |
| n | 2.000 |
| gf | 0.990 |
| gb | -0.786 |
| k | 1.000 |
| δ90 | 9.978 |
| Parameter | Symbol | Range | Description |
|---|---|---|---|
| Absolute magnitude at 1 AU from Sun and Earth | H0 | -5 to 20 | Intrinsic brightness of the comet |
| Photometric slope parameter | n | 2 to 6 | Rate of brightness change with heliocentric distance |
| Forward scattering asymmetry factor | gf |
0.8 to 1 | Degree of forward scattering |
| Backward scattering asymmetry factor | gb |
-1 to -0.5 | Degree of backward scattering |
| Partitioning coefficient | k | 0.8 to 1 | Ratio between forward/backward scattering contributions |
| Dust-to-gas brightness ratio | δ90 | 1 to 10 | Relative contribution of dust scattering to gas emission |
Reference: EPSC-DPS2025-160
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) | End (UTC) | a | b |
|---|---|---|---|
| 2022-10-03 | 2023-01-17 | +12.9255 | -9.332 |
| 2023-01-17 | 2023-05-12 | +7.4344 | -5.338 |
| 2023-05-12 | 2024-02-14 | -1.8399 | +0.708 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Finding Chart
Ephemeris
| Date/Time (UTC) | RA (J2000) | Dec (J2000) | Nearest HIP | Dist from HIP (arcmin) |
|---|---|---|---|---|
| 2026-03-26 00:00 | 19:53:46.98 | -02:29:30.8 | HIP 97768 | 32.79 |
| 2026-03-26 12:00 | 19:53:57.07 | -02:27:37.5 | HIP 97768 | 33.74 |
| 2026-03-27 00:00 | 19:54:07.05 | -02:25:44.3 | HIP 97887 | 34.07 |
| 2026-03-27 12:00 | 19:54:16.92 | -02:23:51.0 | HIP 97887 | 33.08 |
| 2026-03-28 00:00 | 19:54:26.67 | -02:21:57.7 | HIP 97887 | 32.36 |
| 2026-03-28 12:00 | 19:54:36.31 | -02:20:04.4 | HIP 97887 | 31.90 |
| 2026-03-29 00:00 | 19:54:45.84 | -02:18:11.2 | HIP 98074 | 30.04 |
| 2026-03-29 12:00 | 19:54:55.25 | -02:16:18.0 | HIP 98074 | 27.15 |
| 2026-03-30 00:00 | 19:55:04.54 | -02:14:24.8 | HIP 98074 | 24.31 |
| 2026-03-30 12:00 | 19:55:13.72 | -02:12:31.6 | HIP 98074 | 21.52 |
| 2026-03-31 00:00 | 19:55:22.79 | -02:10:38.5 | HIP 98074 | 18.80 |
| 2026-03-31 12:00 | 19:55:31.74 | -02:08:45.4 | HIP 98074 | 16.18 |
| 2026-04-01 00:00 | 19:55:40.57 | -02:06:52.4 | HIP 98074 | 13.68 |
| 2026-04-01 12:00 | 19:55:49.29 | -02:04:59.4 | HIP 98074 | 11.38 |
| 2026-04-02 00:00 | 19:55:57.89 | -02:03:06.5 | HIP 98074 | 9.41 |
| 2026-04-02 12:00 | 19:56:06.38 | -02:01:13.6 | HIP 98074 | 7.98 |
| 2026-04-03 00:00 | 19:56:14.74 | -01:59:20.8 | HIP 98074 | 7.40 |
| 2026-04-03 12:00 | 19:56:22.99 | -01:57:28.1 | HIP 98074 | 7.82 |
| 2026-04-04 00:00 | 19:56:31.12 | -01:55:35.4 | HIP 98074 | 9.08 |
| 2026-04-04 12:00 | 19:56:39.14 | -01:53:42.8 | HIP 98074 | 10.89 |
| 2026-04-05 00:00 | 19:56:47.03 | -01:51:50.4 | HIP 98220 | 12.33 |
| 2026-04-05 12:00 | 19:56:54.80 | -01:49:58.0 | HIP 98220 | 10.80 |
| 2026-04-06 00:00 | 19:57:02.46 | -01:48:05.7 | HIP 98220 | 9.82 |
| 2026-04-06 12:00 | 19:57:09.99 | -01:46:13.5 | HIP 98220 | 9.53 |
| 2026-04-07 00:00 | 19:57:17.41 | -01:44:21.4 | HIP 98220 | 9.98 |
| 2026-04-07 12:00 | 19:57:24.70 | -01:42:29.4 | HIP 98220 | 11.06 |
| 2026-04-08 00:00 | 19:57:31.88 | -01:40:37.6 | HIP 98220 | 12.60 |
| 2026-04-08 12:00 | 19:57:38.93 | -01:38:45.9 | HIP 98220 | 14.44 |
| 2026-04-09 00:00 | 19:57:45.86 | -01:36:54.3 | HIP 98220 | 16.46 |
| 2026-04-09 12:00 | 19:57:52.67 | -01:35:02.8 | HIP 98220 | 18.60 |
| 2026-04-10 00:00 | 19:57:59.35 | -01:33:11.5 | HIP 98220 | 20.82 |
| 2026-04-10 12:00 | 19:58:05.91 | -01:31:20.3 | HIP 98220 | 23.08 |
| 2026-04-11 00:00 | 19:58:12.35 | -01:29:29.3 | HIP 98220 | 25.37 |
| 2026-04-11 12:00 | 19:58:18.67 | -01:27:38.5 | HIP 98161 | 25.50 |
| 2026-04-12 00:00 | 19:58:24.86 | -01:25:47.8 | HIP 98161 | 25.76 |
| 2026-04-12 12:00 | 19:58:30.93 | -01:23:57.3 | HIP 98161 | 26.21 |
| 2026-04-13 00:00 | 19:58:36.87 | -01:22:06.9 | HIP 98410 | 26.20 |
| 2026-04-13 12:00 | 19:58:42.69 | -01:20:16.8 | HIP 98410 | 23.86 |
| 2026-04-14 00:00 | 19:58:48.39 | -01:18:26.8 | HIP 98410 | 21.54 |
| 2026-04-14 12:00 | 19:58:53.95 | -01:16:37.1 | HIP 98410 | 19.24 |
| 2026-04-15 00:00 | 19:58:59.40 | -01:14:47.5 | HIP 98410 | 16.96 |
| 2026-04-15 12:00 | 19:59:04.71 | -01:12:58.2 | HIP 98410 | 14.71 |
| 2026-04-16 00:00 | 19:59:09.90 | -01:11:09.0 | HIP 98410 | 12.49 |