C/2022 E3 (ZTF)
Metadata
| Parameter | Value |
|---|---|
| Designation | C/2022 E3 (ZTF) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2023-01-12T18:50:41.176320Z |
| Orbit solution date (soln_date, UTC) | 2025-07-31T12:12:23Z |
| Obs used | 5330 |
| NEO | - |
| M1 | 10.800 |
| K1 | 4.500 |
| PC | - |
| Discovery observation (MPC, UTC) | 2022-03-02T13:04:07.392000Z |
| Discovery magnitude (MPC) | 17.29 r |
| Discovery observatory (MPC) | I41 · Palomar Mountain–ZTF |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2022-10-21.0000000 |
| e | 1.00030191 |
| q (au) | 1.112244 |
| a (au) | -3684.077283 |
| i (deg) | 109.169481 |
| Ω (om, deg) | 302.555020 |
| ω (w, deg) | 145.814929 |
| M (ma, deg) | -0.000369 |
Magnitude
Scatter + Global Linear
$$ M_a = (10.745 + 2.944\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 10.745 |
| n | 2.944 |
| gf | 1.000 |
| gb | -0.681 |
| k | 0.800 |
| 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 |
|---|---|---|---|
| 2021-07-10 | 2023-01-12 | +2.7726 | -1.340 |
| 2023-01-13 | 2023-03-14 | +4.1829 | -0.918 |
| 2023-03-14 | 2024-02-07 | +4.6483 | -1.569 |
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) |
|---|---|---|---|---|
| 2026-09-20 00:00 | 02:07:25.46 | -63:11:27.9 | HIP 9784 | 32.07 |
| 2026-09-20 12:00 | 02:07:05.89 | -63:13:01.3 | HIP 9784 | 32.87 |
| 2026-09-21 00:00 | 02:06:46.20 | -63:14:33.5 | HIP 9784 | 33.85 |
| 2026-09-21 12:00 | 02:06:26.38 | -63:16:04.5 | HIP 9784 | 34.99 |
| 2026-09-22 00:00 | 02:06:06.43 | -63:17:34.4 | HIP 9469 | 34.81 |
| 2026-09-22 12:00 | 02:05:46.37 | -63:19:03.0 | HIP 9469 | 32.12 |
| 2026-09-23 00:00 | 02:05:26.19 | -63:20:30.5 | HIP 9469 | 29.43 |
| 2026-09-23 12:00 | 02:05:05.89 | -63:21:56.8 | HIP 9469 | 26.74 |
| 2026-09-24 00:00 | 02:04:45.48 | -63:23:21.8 | HIP 9469 | 24.05 |
| 2026-09-24 12:00 | 02:04:24.96 | -63:24:45.7 | HIP 9469 | 21.37 |
| 2026-09-25 00:00 | 02:04:04.32 | -63:26:08.3 | HIP 9469 | 18.70 |
| 2026-09-25 12:00 | 02:03:43.58 | -63:27:29.7 | HIP 9469 | 16.04 |
| 2026-09-26 00:00 | 02:03:22.73 | -63:28:49.8 | HIP 9469 | 13.39 |
| 2026-09-26 12:00 | 02:03:01.77 | -63:30:08.7 | HIP 9469 | 10.76 |
| 2026-09-27 00:00 | 02:02:40.71 | -63:31:26.3 | HIP 9469 | 8.17 |
| 2026-09-27 12:00 | 02:02:19.55 | -63:32:42.7 | HIP 9469 | 5.69 |
| 2026-09-28 00:00 | 02:01:58.29 | -63:33:57.8 | HIP 9469 | 3.52 |
| 2026-09-28 12:00 | 02:01:36.93 | -63:35:11.6 | HIP 9469 | 2.62 |
| 2026-09-29 00:00 | 02:01:15.48 | -63:36:24.1 | HIP 9469 | 3.97 |
| 2026-09-29 12:00 | 02:00:53.93 | -63:37:35.4 | HIP 9469 | 6.24 |
| 2026-09-30 00:00 | 02:00:32.29 | -63:38:45.3 | HIP 9469 | 8.75 |
| 2026-09-30 12:00 | 02:00:10.57 | -63:39:53.9 | HIP 9469 | 11.33 |
| 2026-10-01 00:00 | 01:59:48.75 | -63:41:01.3 | HIP 9469 | 13.95 |
| 2026-10-01 12:00 | 01:59:26.85 | -63:42:07.2 | HIP 9469 | 16.59 |
| 2026-10-02 00:00 | 01:59:04.87 | -63:43:11.9 | HIP 9469 | 19.23 |
| 2026-10-02 12:00 | 01:58:42.81 | -63:44:15.2 | HIP 9469 | 21.87 |
| 2026-10-03 00:00 | 01:58:20.67 | -63:45:17.2 | HIP 9469 | 24.52 |
| 2026-10-03 12:00 | 01:57:58.45 | -63:46:17.9 | HIP 9469 | 27.17 |
| 2026-10-04 00:00 | 01:57:36.16 | -63:47:17.1 | HIP 9469 | 29.82 |
| 2026-10-04 12:00 | 01:57:13.80 | -63:48:15.0 | HIP 9469 | 32.47 |
| 2026-10-05 00:00 | 01:56:51.36 | -63:49:11.6 | HIP 9469 | 35.12 |
| 2026-10-05 12:00 | 01:56:28.86 | -63:50:06.8 | HIP 9469 | 37.76 |
| 2026-10-06 00:00 | 01:56:06.30 | -63:51:00.5 | HIP 9469 | 40.41 |
| 2026-10-06 12:00 | 01:55:43.67 | -63:51:52.9 | HIP 9469 | 43.05 |
| 2026-10-07 00:00 | 01:55:20.99 | -63:52:44.0 | HIP 8623 | 44.99 |
| 2026-10-07 12:00 | 01:54:58.24 | -63:53:33.6 | HIP 8623 | 44.17 |
| 2026-10-08 00:00 | 01:54:35.45 | -63:54:21.8 | HIP 8512 | 42.56 |
| 2026-10-08 12:00 | 01:54:12.60 | -63:55:08.6 | HIP 8512 | 40.21 |
| 2026-10-09 00:00 | 01:53:49.70 | -63:55:53.9 | HIP 8512 | 37.90 |
| 2026-10-09 12:00 | 01:53:26.75 | -63:56:37.9 | HIP 8512 | 35.66 |
| 2026-10-10 00:00 | 01:53:03.76 | -63:57:20.4 | HIP 8512 | 33.48 |
| 2026-10-10 12:00 | 01:52:40.73 | -63:58:01.5 | HIP 8512 | 31.39 |
| 2026-10-11 00:00 | 01:52:17.66 | -63:58:41.2 | HIP 8512 | 29.40 |