C/2022 E2 (ATLAS)
Metadata
| Parameter | Value |
|---|---|
| Designation | C/2022 E2 (ATLAS) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2024-09-14T02:54:18.374400Z |
| Orbit solution date (soln_date, UTC) | 2026-01-13T08:12:19Z |
| Obs used | 5479 |
| NEO | - |
| M1 | 8.400 |
| K1 | 5.750 |
| PC | - |
| Discovery observation (MPC, UTC) | 2022-03-07T02:52:22.339200Z |
| Discovery magnitude (MPC) | 18.76 c |
| Discovery observatory (MPC) | W68 · ATLAS Chile, Rio Hurtado |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2024-07-10.0000000 |
| e | 1.00091934 |
| q (au) | 3.666307 |
| a (au) | -3987.983847 |
| i (deg) | 137.127383 |
| Ω (om, deg) | 125.371638 |
| ω (w, deg) | 41.719470 |
| M (ma, deg) | -0.000259 |
Magnitude
Scatter + Global Linear
$$ M_a = (7.039 + 2.797\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 7.039 |
| n | 2.797 |
| gf | 1.000 |
| gb | -0.845 |
| k | 0.998 |
| δ90 | 10.000 |
| 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 |
|---|---|---|---|
| 2022-02-23 | 2024-01-03 | +2.8411 | -2.343 |
| 2024-01-03 | 2024-09-14 | +5.8229 | -3.868 |
| 2024-09-15 | 2026-01-27 | +3.4938 | -2.141 |
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) |
|---|---|---|---|---|
| 2026-02-03 00:00 | 22:41:46.85 | +29:00:23.3 | HIP 112051 | 18.08 |
| 2026-02-03 12:00 | 22:41:59.62 | +28:58:51.1 | HIP 112051 | 19.85 |
| 2026-02-04 00:00 | 22:42:12.42 | +28:57:20.8 | HIP 112051 | 21.92 |
| 2026-02-04 12:00 | 22:42:25.25 | +28:55:52.3 | HIP 112051 | 24.21 |
| 2026-02-05 00:00 | 22:42:38.11 | +28:54:25.6 | HIP 112051 | 26.65 |
| 2026-02-05 12:00 | 22:42:51.00 | +28:53:00.7 | HIP 112235 | 27.64 |
| 2026-02-06 00:00 | 22:43:03.92 | +28:51:37.7 | HIP 112235 | 27.54 |
| 2026-02-06 12:00 | 22:43:16.87 | +28:50:16.4 | HIP 112235 | 27.76 |
| 2026-02-07 00:00 | 22:43:29.85 | +28:48:56.9 | HIP 112235 | 28.29 |
| 2026-02-07 12:00 | 22:43:42.85 | +28:47:39.2 | HIP 112235 | 29.13 |
| 2026-02-08 00:00 | 22:43:55.87 | +28:46:23.2 | HIP 112399 | 27.82 |
| 2026-02-08 12:00 | 22:44:08.92 | +28:45:09.0 | HIP 112399 | 24.76 |
| 2026-02-09 00:00 | 22:44:22.00 | +28:43:56.5 | HIP 112399 | 21.72 |
| 2026-02-09 12:00 | 22:44:35.09 | +28:42:45.8 | HIP 112399 | 18.69 |
| 2026-02-10 00:00 | 22:44:48.21 | +28:41:36.8 | HIP 112399 | 15.70 |
| 2026-02-10 12:00 | 22:45:01.35 | +28:40:29.5 | HIP 112399 | 12.75 |
| 2026-02-11 00:00 | 22:45:14.50 | +28:39:23.9 | HIP 112399 | 9.88 |
| 2026-02-11 12:00 | 22:45:27.68 | +28:38:20.0 | HIP 112399 | 7.18 |
| 2026-02-12 00:00 | 22:45:40.86 | +28:37:17.7 | HIP 112399 | 4.93 |
| 2026-02-12 12:00 | 22:45:54.07 | +28:36:17.2 | HIP 112399 | 3.96 |
| 2026-02-13 00:00 | 22:46:07.29 | +28:35:18.3 | HIP 112399 | 5.07 |
| 2026-02-13 12:00 | 22:46:20.52 | +28:34:21.0 | HIP 112399 | 7.35 |
| 2026-02-14 00:00 | 22:46:33.77 | +28:33:25.4 | HIP 112471 | 5.03 |
| 2026-02-14 12:00 | 22:46:47.03 | +28:32:31.5 | HIP 112471 | 2.08 |
| 2026-02-15 00:00 | 22:47:00.29 | +28:31:39.1 | HIP 112471 | 1.40 |
| 2026-02-15 12:00 | 22:47:13.57 | +28:30:48.4 | HIP 112471 | 4.25 |
| 2026-02-16 00:00 | 22:47:26.86 | +28:29:59.2 | HIP 112471 | 7.25 |
| 2026-02-16 12:00 | 22:47:40.15 | +28:29:11.7 | HIP 112471 | 10.27 |
| 2026-02-17 00:00 | 22:47:53.45 | +28:28:25.7 | HIP 112471 | 13.29 |
| 2026-02-17 12:00 | 22:48:06.75 | +28:27:41.3 | HIP 112471 | 16.30 |
| 2026-02-18 00:00 | 22:48:20.06 | +28:26:58.4 | HIP 112619 | 16.72 |
| 2026-02-18 12:00 | 22:48:33.37 | +28:26:17.1 | HIP 112619 | 17.21 |
| 2026-02-19 00:00 | 22:48:46.68 | +28:25:37.4 | HIP 112619 | 18.16 |
| 2026-02-19 12:00 | 22:49:00.00 | +28:24:59.1 | HIP 112614 | 18.89 |
| 2026-02-20 00:00 | 22:49:13.30 | +28:24:22.4 | HIP 112614 | 19.57 |
| 2026-02-20 12:00 | 22:49:26.61 | +28:23:47.2 | HIP 112614 | 20.69 |
| 2026-02-21 00:00 | 22:49:39.92 | +28:23:13.5 | HIP 112614 | 22.18 |
| 2026-02-21 12:00 | 22:49:53.23 | +28:22:41.2 | HIP 112614 | 23.96 |
| 2026-02-22 00:00 | 22:50:06.53 | +28:22:10.4 | HIP 112614 | 25.98 |
| 2026-02-22 12:00 | 22:50:19.82 | +28:21:41.1 | HIP 112614 | 28.18 |
| 2026-02-23 00:00 | 22:50:33.11 | +28:21:13.2 | HIP 112614 | 30.52 |
| 2026-02-23 12:00 | 22:50:46.39 | +28:20:46.8 | HIP 112614 | 32.97 |
| 2026-02-24 00:00 | 22:50:59.66 | +28:20:21.8 | HIP 112614 | 35.50 |