| Parameter |
Value |
| Designation |
C/2023 K1 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2023-09-07T17:57:17.956800Z |
| Orbit solution date (soln_date, UTC) |
2024-04-13T16:42:46Z |
| Obs used |
218 |
| NEO |
- |
| M1 |
6.200 |
| K1 |
27.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2023-05-27T02:15:06.998400Z |
| Discovery magnitude (MPC) |
18.64 c |
| Discovery observatory (MPC) |
M22 · ATLAS South Africa, Sutherland |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2023-07-23.0000000 |
| e |
0.99718017 |
| q (au) |
2.039540 |
| a (au) |
723.284257 |
| i (deg) |
137.998404 |
| Ω (om, deg) |
223.706343 |
| ω (w, deg) |
337.472407 |
| M (ma, deg) |
359.997631 |
Magnitude
Scatter + Global Linear
$$
M_a = (9.725 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.725 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.553 |
| k |
1.000 |
| 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 |
| 2023-05-27 |
2023-09-02 |
+17.2597 |
-6.056 |
| 2023-09-09 |
2024-03-19 |
+19.3353 |
-8.589 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
08:47:03.93 |
+56:38:30.7 |
HIP 43289 |
25.25 |
| 2026-07-29 12:00 |
08:47:19.15 |
+56:38:00.2 |
HIP 43289 |
23.51 |
| 2026-07-30 00:00 |
08:47:34.38 |
+56:37:30.4 |
HIP 43289 |
21.85 |
| 2026-07-30 12:00 |
08:47:49.60 |
+56:37:01.3 |
HIP 43289 |
20.30 |
| 2026-07-31 00:00 |
08:48:04.81 |
+56:36:33.0 |
HIP 43289 |
18.87 |
| 2026-07-31 12:00 |
08:48:20.02 |
+56:36:05.5 |
HIP 43289 |
17.61 |
| 2026-08-01 00:00 |
08:48:35.22 |
+56:35:38.8 |
HIP 43289 |
16.55 |
| 2026-08-01 12:00 |
08:48:50.41 |
+56:35:12.8 |
HIP 43289 |
15.72 |
| 2026-08-02 00:00 |
08:49:05.60 |
+56:34:47.5 |
HIP 43289 |
15.16 |
| 2026-08-02 12:00 |
08:49:20.77 |
+56:34:23.0 |
HIP 43289 |
14.90 |
| 2026-08-03 00:00 |
08:49:35.93 |
+56:33:59.3 |
HIP 43289 |
14.96 |
| 2026-08-03 12:00 |
08:49:51.09 |
+56:33:36.4 |
HIP 43289 |
15.33 |
| 2026-08-04 00:00 |
08:50:06.23 |
+56:33:14.2 |
HIP 43289 |
15.99 |
| 2026-08-04 12:00 |
08:50:21.36 |
+56:32:52.8 |
HIP 43289 |
16.90 |
| 2026-08-05 00:00 |
08:50:36.47 |
+56:32:32.2 |
HIP 43289 |
18.03 |
| 2026-08-05 12:00 |
08:50:51.57 |
+56:32:12.4 |
HIP 43289 |
19.33 |
| 2026-08-06 00:00 |
08:51:06.66 |
+56:31:53.3 |
HIP 43289 |
20.77 |
| 2026-08-06 12:00 |
08:51:21.73 |
+56:31:35.1 |
HIP 43376 |
21.78 |
| 2026-08-07 00:00 |
08:51:36.78 |
+56:31:17.6 |
HIP 43376 |
22.59 |
| 2026-08-07 12:00 |
08:51:51.82 |
+56:31:00.9 |
HIP 43376 |
23.58 |
| 2026-08-08 00:00 |
08:52:06.84 |
+56:30:45.0 |
HIP 43376 |
24.71 |
| 2026-08-08 12:00 |
08:52:21.83 |
+56:30:29.9 |
HIP 43376 |
25.97 |
| 2026-08-09 00:00 |
08:52:36.81 |
+56:30:15.6 |
HIP 43376 |
27.34 |
| 2026-08-09 12:00 |
08:52:51.77 |
+56:30:02.1 |
HIP 43376 |
28.81 |
| 2026-08-10 00:00 |
08:53:06.70 |
+56:29:49.3 |
HIP 43884 |
28.24 |
| 2026-08-10 12:00 |
08:53:21.61 |
+56:29:37.4 |
HIP 43884 |
26.32 |
| 2026-08-11 00:00 |
08:53:36.50 |
+56:29:26.3 |
HIP 43884 |
24.42 |
| 2026-08-11 12:00 |
08:53:51.36 |
+56:29:16.0 |
HIP 43884 |
22.55 |
| 2026-08-12 00:00 |
08:54:06.20 |
+56:29:06.6 |
HIP 43884 |
20.71 |
| 2026-08-12 12:00 |
08:54:21.01 |
+56:28:57.9 |
HIP 43884 |
18.91 |
| 2026-08-13 00:00 |
08:54:35.79 |
+56:28:50.0 |
HIP 43884 |
17.16 |
| 2026-08-13 12:00 |
08:54:50.54 |
+56:28:43.0 |
HIP 43884 |
15.48 |
| 2026-08-14 00:00 |
08:55:05.26 |
+56:28:36.8 |
HIP 43884 |
13.90 |
| 2026-08-14 12:00 |
08:55:19.95 |
+56:28:31.4 |
HIP 43884 |
12.43 |
| 2026-08-15 00:00 |
08:55:34.61 |
+56:28:26.8 |
HIP 43884 |
11.13 |
| 2026-08-15 12:00 |
08:55:49.24 |
+56:28:23.0 |
HIP 43884 |
10.07 |
| 2026-08-16 00:00 |
08:56:03.83 |
+56:28:20.1 |
HIP 43884 |
9.31 |
| 2026-08-16 12:00 |
08:56:18.39 |
+56:28:18.0 |
HIP 43884 |
8.94 |
| 2026-08-17 00:00 |
08:56:32.91 |
+56:28:16.7 |
HIP 43884 |
8.99 |
| 2026-08-17 12:00 |
08:56:47.40 |
+56:28:16.3 |
HIP 43884 |
9.46 |
| 2026-08-18 00:00 |
08:57:01.85 |
+56:28:16.7 |
HIP 43884 |
10.29 |
| 2026-08-18 12:00 |
08:57:16.26 |
+56:28:17.9 |
HIP 43884 |
11.40 |
| 2026-08-19 00:00 |
08:57:30.63 |
+56:28:20.0 |
HIP 43884 |
12.71 |