| Parameter |
Value |
| Designation |
C/2023 E1 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2023-07-01T02:34:44.604480Z |
| Orbit solution date (soln_date, UTC) |
2024-02-17T03:13:27Z |
| Obs used |
3004 |
| NEO |
Yes |
| M1 |
16.200 |
| K1 |
7.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2023-03-01T00:05:50.179200Z |
| Discovery magnitude (MPC) |
18.82 o |
| Discovery observatory (MPC) |
M22 · ATLAS South Africa, Sutherland |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2023-07-02.0000000 |
| e |
0.94690275 |
| q (au) |
1.026605 |
| a (au) |
19.334429 |
| i (deg) |
38.312983 |
| Ω (om, deg) |
164.574212 |
| ω (w, deg) |
105.894615 |
| M (ma, deg) |
0.010347 |
Magnitude
Scatter + Global Linear
$$
M_a = (15.216 + 5.450\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
15.216 |
| n |
5.450 |
| gf |
0.997 |
| gb |
-0.697 |
| k |
0.942 |
| 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 |
| 2022-12-25 |
2023-06-30 |
+7.6115 |
-1.812 |
| 2023-07-01 |
2023-12-11 |
-0.5124 |
-1.544 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
04:03:12.44 |
-13:15:47.3 |
HIP 19011 |
33.03 |
| 2026-06-01 12:00 |
04:03:25.00 |
-13:15:35.2 |
HIP 19011 |
31.37 |
| 2026-06-02 00:00 |
04:03:37.55 |
-13:15:23.8 |
HIP 19011 |
29.95 |
| 2026-06-02 12:00 |
04:03:50.07 |
-13:15:13.2 |
HIP 19011 |
28.80 |
| 2026-06-03 00:00 |
04:04:02.58 |
-13:15:03.4 |
HIP 19011 |
27.95 |
| 2026-06-03 12:00 |
04:04:15.08 |
-13:14:54.3 |
HIP 19011 |
27.43 |
| 2026-06-04 00:00 |
04:04:27.55 |
-13:14:46.0 |
HIP 19011 |
27.25 |
| 2026-06-04 12:00 |
04:04:40.01 |
-13:14:38.5 |
HIP 19011 |
27.43 |
| 2026-06-05 00:00 |
04:04:52.45 |
-13:14:31.7 |
HIP 19162 |
24.44 |
| 2026-06-05 12:00 |
04:05:04.87 |
-13:14:25.7 |
HIP 19162 |
21.42 |
| 2026-06-06 00:00 |
04:05:17.27 |
-13:14:20.5 |
HIP 19162 |
18.41 |
| 2026-06-06 12:00 |
04:05:29.64 |
-13:14:16.0 |
HIP 19162 |
15.40 |
| 2026-06-07 00:00 |
04:05:42.00 |
-13:14:12.3 |
HIP 19162 |
12.41 |
| 2026-06-07 12:00 |
04:05:54.34 |
-13:14:09.4 |
HIP 19162 |
9.43 |
| 2026-06-08 00:00 |
04:06:06.65 |
-13:14:07.2 |
HIP 19162 |
6.48 |
| 2026-06-08 12:00 |
04:06:18.94 |
-13:14:05.9 |
HIP 19162 |
3.62 |
| 2026-06-09 00:00 |
04:06:31.21 |
-13:14:05.2 |
HIP 19162 |
1.47 |
| 2026-06-09 12:00 |
04:06:43.45 |
-13:14:05.4 |
HIP 19162 |
3.01 |
| 2026-06-10 00:00 |
04:06:55.67 |
-13:14:06.3 |
HIP 19162 |
5.80 |
| 2026-06-10 12:00 |
04:07:07.87 |
-13:14:08.1 |
HIP 19162 |
8.71 |
| 2026-06-11 00:00 |
04:07:20.03 |
-13:14:10.5 |
HIP 19162 |
11.65 |
| 2026-06-11 12:00 |
04:07:32.18 |
-13:14:13.8 |
HIP 19162 |
14.59 |
| 2026-06-12 00:00 |
04:07:44.29 |
-13:14:17.8 |
HIP 19162 |
17.53 |
| 2026-06-12 12:00 |
04:07:56.38 |
-13:14:22.7 |
HIP 19381 |
17.41 |
| 2026-06-13 00:00 |
04:08:08.44 |
-13:14:28.3 |
HIP 19381 |
14.51 |
| 2026-06-13 12:00 |
04:08:20.48 |
-13:14:34.6 |
HIP 19381 |
11.63 |
| 2026-06-14 00:00 |
04:08:32.48 |
-13:14:41.8 |
HIP 19381 |
8.78 |
| 2026-06-14 12:00 |
04:08:44.46 |
-13:14:49.7 |
HIP 19381 |
6.00 |
| 2026-06-15 00:00 |
04:08:56.40 |
-13:14:58.4 |
HIP 19381 |
3.45 |
| 2026-06-15 12:00 |
04:09:08.31 |
-13:15:07.9 |
HIP 19381 |
2.17 |
| 2026-06-16 00:00 |
04:09:20.19 |
-13:15:18.2 |
HIP 19381 |
3.78 |
| 2026-06-16 12:00 |
04:09:32.04 |
-13:15:29.2 |
HIP 19381 |
6.36 |
| 2026-06-17 00:00 |
04:09:43.86 |
-13:15:41.0 |
HIP 19381 |
9.12 |
| 2026-06-17 12:00 |
04:09:55.64 |
-13:15:53.6 |
HIP 19381 |
11.93 |
| 2026-06-18 00:00 |
04:10:07.39 |
-13:16:07.0 |
HIP 19381 |
14.75 |
| 2026-06-18 12:00 |
04:10:19.11 |
-13:16:21.1 |
HIP 19381 |
17.58 |
| 2026-06-19 00:00 |
04:10:30.79 |
-13:16:36.0 |
HIP 19381 |
20.41 |
| 2026-06-19 12:00 |
04:10:42.43 |
-13:16:51.7 |
HIP 19608 |
20.48 |
| 2026-06-20 00:00 |
04:10:54.04 |
-13:17:08.2 |
HIP 19608 |
17.76 |
| 2026-06-20 12:00 |
04:11:05.61 |
-13:17:25.4 |
HIP 19608 |
15.10 |
| 2026-06-21 00:00 |
04:11:17.15 |
-13:17:43.4 |
HIP 19608 |
12.51 |
| 2026-06-21 12:00 |
04:11:28.64 |
-13:18:02.2 |
HIP 19608 |
10.08 |
| 2026-06-22 00:00 |
04:11:40.10 |
-13:18:21.7 |
HIP 19608 |
7.91 |