C/2022 E2 (ATLAS)
Metadata
| Parameter | Value |
|---|---|
| Designation | C/2022 E2 (ATLAS) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2024-09-14T02:56:23.352000Z |
| Orbit solution date (soln_date, UTC) | 2026-03-21T13:42:21Z |
| Obs used | 5539 |
| 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) | 2024-07-16.0000000 |
| e | 1.00093542 |
| q (au) | 3.666305 |
| a (au) | -3919.416581 |
| i (deg) | 137.127706 |
| Ω (om, deg) | 125.371905 |
| ω (w, deg) | 41.720008 |
| M (ma, deg) | -0.000241 |
Magnitude
Scatter + Global Linear
$$ M_a = (6.638 + 3.007\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 6.638 |
| n | 3.007 |
| gf | 1.000 |
| gb | -0.872 |
| k | 0.999 |
| 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 | 2024-01-05 | +2.2828 | -2.026 |
| 2024-01-05 | 2024-09-14 | +6.7868 | -4.471 |
| 2024-09-15 | 2026-03-19 | +4.2070 | -2.598 |
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 | 23:03:28.01 | +28:32:39.1 | HIP 113881 | 28.00 |
| 2026-03-26 12:00 | 23:03:39.14 | +28:33:22.9 | HIP 113881 | 28.48 |
| 2026-03-27 00:00 | 23:03:50.21 | +28:34:07.5 | HIP 113992 | 27.60 |
| 2026-03-27 12:00 | 23:04:01.21 | +28:34:53.0 | HIP 113992 | 26.85 |
| 2026-03-28 00:00 | 23:04:12.16 | +28:35:39.3 | HIP 113992 | 26.34 |
| 2026-03-28 12:00 | 23:04:23.03 | +28:36:26.4 | HIP 114037 | 25.16 |
| 2026-03-29 00:00 | 23:04:33.85 | +28:37:14.3 | HIP 114037 | 23.04 |
| 2026-03-29 12:00 | 23:04:44.59 | +28:38:03.0 | HIP 114037 | 21.00 |
| 2026-03-30 00:00 | 23:04:55.28 | +28:38:52.4 | HIP 114037 | 19.07 |
| 2026-03-30 12:00 | 23:05:05.89 | +28:39:42.7 | HIP 114037 | 17.28 |
| 2026-03-31 00:00 | 23:05:16.44 | +28:40:33.7 | HIP 114037 | 15.66 |
| 2026-03-31 12:00 | 23:05:26.91 | +28:41:25.5 | HIP 114037 | 14.27 |
| 2026-04-01 00:00 | 23:05:37.32 | +28:42:18.1 | HIP 114037 | 13.19 |
| 2026-04-01 12:00 | 23:05:47.66 | +28:43:11.3 | HIP 114037 | 12.48 |
| 2026-04-02 00:00 | 23:05:57.93 | +28:44:05.4 | HIP 114037 | 12.20 |
| 2026-04-02 12:00 | 23:06:08.12 | +28:45:00.1 | HIP 114037 | 12.38 |
| 2026-04-03 00:00 | 23:06:18.25 | +28:45:55.6 | HIP 114037 | 13.00 |
| 2026-04-03 12:00 | 23:06:28.30 | +28:46:51.8 | HIP 114037 | 13.98 |
| 2026-04-04 00:00 | 23:06:38.27 | +28:47:48.7 | HIP 114037 | 15.26 |
| 2026-04-04 12:00 | 23:06:48.17 | +28:48:46.2 | HIP 114037 | 16.76 |
| 2026-04-05 00:00 | 23:06:58.00 | +28:49:44.5 | HIP 114037 | 18.43 |
| 2026-04-05 12:00 | 23:07:07.75 | +28:50:43.5 | HIP 114037 | 20.21 |
| 2026-04-06 00:00 | 23:07:17.43 | +28:51:43.1 | HIP 114037 | 22.08 |
| 2026-04-06 12:00 | 23:07:27.02 | +28:52:43.4 | HIP 114263 | 21.62 |
| 2026-04-07 00:00 | 23:07:36.54 | +28:53:44.4 | HIP 114263 | 19.55 |
| 2026-04-07 12:00 | 23:07:45.98 | +28:54:46.0 | HIP 114263 | 17.55 |
| 2026-04-08 00:00 | 23:07:55.34 | +28:55:48.2 | HIP 114263 | 15.64 |
| 2026-04-08 12:00 | 23:08:04.61 | +28:56:51.1 | HIP 114263 | 13.83 |
| 2026-04-09 00:00 | 23:08:13.81 | +28:57:54.6 | HIP 114263 | 12.18 |
| 2026-04-09 12:00 | 23:08:22.92 | +28:58:58.7 | HIP 114263 | 10.75 |
| 2026-04-10 00:00 | 23:08:31.95 | +29:00:03.5 | HIP 114263 | 9.63 |
| 2026-04-10 12:00 | 23:08:40.90 | +29:01:08.8 | HIP 114263 | 8.93 |
| 2026-04-11 00:00 | 23:08:49.76 | +29:02:14.7 | HIP 114263 | 8.75 |
| 2026-04-11 12:00 | 23:08:58.53 | +29:03:21.3 | HIP 114263 | 9.10 |
| 2026-04-12 00:00 | 23:09:07.22 | +29:04:28.4 | HIP 114263 | 9.92 |
| 2026-04-12 12:00 | 23:09:15.82 | +29:05:36.0 | HIP 114263 | 11.10 |
| 2026-04-13 00:00 | 23:09:24.33 | +29:06:44.2 | HIP 114263 | 12.54 |
| 2026-04-13 12:00 | 23:09:32.75 | +29:07:53.0 | HIP 114263 | 14.14 |
| 2026-04-14 00:00 | 23:09:41.08 | +29:09:02.3 | HIP 114263 | 15.86 |
| 2026-04-14 12:00 | 23:09:49.32 | +29:10:12.2 | HIP 114263 | 17.65 |
| 2026-04-15 00:00 | 23:09:57.47 | +29:11:22.5 | HIP 114263 | 19.50 |
| 2026-04-15 12:00 | 23:10:05.52 | +29:12:33.4 | HIP 114263 | 21.38 |
| 2026-04-16 00:00 | 23:10:13.49 | +29:13:44.8 | HIP 114263 | 23.28 |