C/2022 E2 (ATLAS)
Metadata
| Parameter | Value |
|---|---|
| Designation | C/2022 E2 (ATLAS) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2024-09-14T03:03:34.816320Z |
| Orbit solution date (soln_date, UTC) | 2026-07-28T14:12:17Z |
| Obs used | 5720 |
| NEO | - |
| M1 | 8.100 |
| K1 | 6.250 |
| PC | 0.030 |
| 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) | 2024-08-08.0000000 |
| e | 1.00099718 |
| q (au) | 3.666298 |
| a (au) | -3676.677251 |
| i (deg) | 137.129148 |
| Ω (om, deg) | 125.373242 |
| ω (w, deg) | 41.722144 |
| M (ma, deg) | -0.000164 |
Magnitude
Scatter + Global Linear
$$ M_a = (6.501 + 3.094\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 6.501 |
| n | 3.094 |
| gf | 1.000 |
| gb | -0.873 |
| 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 | +2.0665 | -1.895 |
| 2024-01-05 | 2024-09-14 | +6.6727 | -4.401 |
| 2024-09-15 | 2026-07-28 | +3.2778 | -2.022 |
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) |
|---|---|---|---|---|
| 2026-07-29 00:00 | 22:46:46.64 | +31:56:45.8 | HIP 112531 | 10.19 |
| 2026-07-29 12:00 | 22:46:23.67 | +31:55:37.8 | HIP 112531 | 15.17 |
| 2026-07-30 00:00 | 22:46:00.59 | +31:54:27.9 | HIP 112531 | 20.20 |
| 2026-07-30 12:00 | 22:45:37.41 | +31:53:16.0 | HIP 112531 | 25.26 |
| 2026-07-31 00:00 | 22:45:14.12 | +31:52:02.1 | HIP 112218 | 29.53 |
| 2026-07-31 12:00 | 22:44:50.73 | +31:50:46.2 | HIP 112218 | 27.46 |
| 2026-08-01 00:00 | 22:44:27.25 | +31:49:28.4 | HIP 112218 | 26.27 |
| 2026-08-01 12:00 | 22:44:03.67 | +31:48:08.6 | HIP 112084 | 25.24 |
| 2026-08-02 00:00 | 22:43:40.00 | +31:46:46.8 | HIP 112084 | 20.03 |
| 2026-08-02 12:00 | 22:43:16.23 | +31:45:23.0 | HIP 112084 | 14.79 |
| 2026-08-03 00:00 | 22:42:52.38 | +31:43:57.3 | HIP 112084 | 9.53 |
| 2026-08-03 12:00 | 22:42:28.43 | +31:42:29.5 | HIP 112084 | 4.27 |
| 2026-08-04 00:00 | 22:42:04.40 | +31:40:59.7 | HIP 112084 | 1.32 |
| 2026-08-04 12:00 | 22:41:40.29 | +31:39:27.9 | HIP 112084 | 6.51 |
| 2026-08-05 00:00 | 22:41:16.09 | +31:37:54.1 | HIP 112084 | 11.88 |
| 2026-08-05 12:00 | 22:40:51.82 | +31:36:18.2 | HIP 111928 | 12.90 |
| 2026-08-06 00:00 | 22:40:27.47 | +31:34:40.4 | HIP 111928 | 12.69 |
| 2026-08-06 12:00 | 22:40:03.04 | +31:33:00.5 | HIP 111928 | 14.69 |
| 2026-08-07 00:00 | 22:39:38.54 | +31:31:18.5 | HIP 111928 | 18.21 |
| 2026-08-07 12:00 | 22:39:13.97 | +31:29:34.6 | HIP 111878 | 21.72 |
| 2026-08-08 00:00 | 22:38:49.33 | +31:27:48.6 | HIP 111878 | 22.21 |
| 2026-08-08 12:00 | 22:38:24.63 | +31:26:00.5 | HIP 111878 | 24.00 |
| 2026-08-09 00:00 | 22:37:59.86 | +31:24:10.5 | HIP 111878 | 26.85 |
| 2026-08-09 12:00 | 22:37:35.03 | +31:22:18.3 | HIP 111878 | 30.47 |
| 2026-08-10 00:00 | 22:37:10.14 | +31:20:24.1 | HIP 111619 | 33.35 |
| 2026-08-10 12:00 | 22:36:45.20 | +31:18:27.9 | HIP 111619 | 30.98 |
| 2026-08-11 00:00 | 22:36:20.20 | +31:16:29.7 | HIP 111483 | 26.93 |
| 2026-08-11 12:00 | 22:35:55.15 | +31:14:29.3 | HIP 111483 | 22.63 |
| 2026-08-12 00:00 | 22:35:30.06 | +31:12:27.0 | HIP 111483 | 19.04 |
| 2026-08-12 12:00 | 22:35:04.92 | +31:10:22.6 | HIP 111483 | 16.68 |
| 2026-08-13 00:00 | 22:34:39.73 | +31:08:16.2 | HIP 111483 | 16.11 |
| 2026-08-13 12:00 | 22:34:14.50 | +31:06:07.7 | HIP 111352 | 13.90 |
| 2026-08-14 00:00 | 22:33:49.24 | +31:03:57.2 | HIP 111352 | 13.47 |
| 2026-08-14 12:00 | 22:33:23.94 | +31:01:44.6 | HIP 111352 | 15.45 |
| 2026-08-15 00:00 | 22:32:58.61 | +30:59:30.1 | HIP 111235 | 13.09 |
| 2026-08-15 12:00 | 22:32:33.25 | +30:57:13.5 | HIP 111235 | 11.41 |
| 2026-08-16 00:00 | 22:32:07.87 | +30:54:54.9 | HIP 111235 | 12.61 |
| 2026-08-16 12:00 | 22:31:42.45 | +30:52:34.2 | HIP 111235 | 16.09 |
| 2026-08-17 00:00 | 22:31:17.02 | +30:50:11.6 | HIP 111235 | 20.75 |
| 2026-08-17 12:00 | 22:30:51.57 | +30:47:47.0 | HIP 111235 | 25.97 |
| 2026-08-18 00:00 | 22:30:26.10 | +30:45:20.4 | HIP 111075 | 27.87 |
| 2026-08-18 12:00 | 22:30:00.62 | +30:42:51.8 | HIP 111075 | 30.13 |
| 2026-08-19 00:00 | 22:29:35.12 | +30:40:21.3 | HIP 110822 | 32.09 |