C/2023 K1 (ATLAS)
| 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 |
-0.500 |
| 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) |
| 2026-02-03 00:00 |
09:27:49.72 |
+64:14:24.4 |
HIP 46347 |
8.41 |
| 2026-02-03 12:00 |
09:27:08.29 |
+64:15:36.9 |
HIP 46347 |
5.12 |
| 2026-02-04 00:00 |
09:26:26.83 |
+64:16:47.1 |
HIP 46347 |
5.03 |
| 2026-02-04 12:00 |
09:25:45.35 |
+64:17:55.0 |
HIP 46347 |
8.23 |
| 2026-02-05 00:00 |
09:25:03.85 |
+64:19:00.6 |
HIP 46347 |
12.37 |
| 2026-02-05 12:00 |
09:24:22.33 |
+64:20:03.9 |
HIP 46347 |
16.77 |
| 2026-02-06 00:00 |
09:23:40.81 |
+64:21:04.8 |
HIP 46347 |
21.26 |
| 2026-02-06 12:00 |
09:22:59.28 |
+64:22:03.5 |
HIP 45774 |
21.78 |
| 2026-02-07 00:00 |
09:22:17.76 |
+64:22:59.9 |
HIP 45774 |
18.39 |
| 2026-02-07 12:00 |
09:21:36.25 |
+64:23:53.9 |
HIP 45774 |
15.62 |
| 2026-02-08 00:00 |
09:20:54.75 |
+64:24:45.7 |
HIP 45774 |
13.83 |
| 2026-02-08 12:00 |
09:20:13.28 |
+64:25:35.1 |
HIP 45774 |
13.39 |
| 2026-02-09 00:00 |
09:19:31.83 |
+64:26:22.2 |
HIP 45774 |
14.42 |
| 2026-02-09 12:00 |
09:18:50.42 |
+64:27:07.1 |
HIP 45774 |
16.64 |
| 2026-02-10 00:00 |
09:18:09.05 |
+64:27:49.6 |
HIP 45774 |
19.64 |
| 2026-02-10 12:00 |
09:17:27.72 |
+64:28:29.8 |
HIP 45774 |
23.12 |
| 2026-02-11 00:00 |
09:16:46.44 |
+64:29:07.7 |
HIP 45774 |
26.88 |
| 2026-02-11 12:00 |
09:16:05.23 |
+64:29:43.4 |
HIP 45207 |
25.83 |
| 2026-02-12 00:00 |
09:15:24.07 |
+64:30:16.7 |
HIP 45207 |
21.96 |
| 2026-02-12 12:00 |
09:14:42.99 |
+64:30:47.8 |
HIP 45207 |
18.40 |
| 2026-02-13 00:00 |
09:14:01.98 |
+64:31:16.5 |
HIP 45207 |
15.34 |
| 2026-02-13 12:00 |
09:13:21.05 |
+64:31:43.0 |
HIP 45207 |
13.11 |
| 2026-02-14 00:00 |
09:12:40.21 |
+64:32:07.3 |
HIP 45207 |
12.19 |
| 2026-02-14 12:00 |
09:11:59.46 |
+64:32:29.2 |
HIP 45207 |
12.82 |
| 2026-02-15 00:00 |
09:11:18.82 |
+64:32:48.9 |
HIP 45207 |
14.81 |
| 2026-02-15 12:00 |
09:10:38.27 |
+64:33:06.4 |
HIP 44844 |
15.63 |
| 2026-02-16 00:00 |
09:09:57.84 |
+64:33:21.6 |
HIP 44844 |
11.28 |
| 2026-02-16 12:00 |
09:09:17.52 |
+64:33:34.6 |
HIP 44844 |
6.95 |
| 2026-02-17 00:00 |
09:08:37.32 |
+64:33:45.4 |
HIP 44844 |
2.65 |
| 2026-02-17 12:00 |
09:07:57.26 |
+64:33:54.0 |
HIP 44844 |
1.72 |
| 2026-02-18 00:00 |
09:07:17.32 |
+64:34:00.3 |
HIP 44844 |
5.98 |
| 2026-02-18 12:00 |
09:06:37.52 |
+64:34:04.5 |
HIP 44844 |
10.25 |
| 2026-02-19 00:00 |
09:05:57.87 |
+64:34:06.5 |
HIP 44666 |
12.72 |
| 2026-02-19 12:00 |
09:05:18.37 |
+64:34:06.3 |
HIP 44666 |
13.77 |
| 2026-02-20 00:00 |
09:04:39.02 |
+64:34:04.0 |
HIP 44666 |
15.92 |
| 2026-02-20 12:00 |
09:03:59.83 |
+64:33:59.5 |
HIP 44666 |
18.80 |
| 2026-02-21 00:00 |
09:03:20.80 |
+64:33:52.9 |
HIP 44666 |
22.11 |
| 2026-02-21 12:00 |
09:02:41.95 |
+64:33:44.2 |
HIP 44666 |
25.67 |
| 2026-02-22 00:00 |
09:02:03.26 |
+64:33:33.4 |
HIP 44666 |
29.39 |
| 2026-02-22 12:00 |
09:01:24.76 |
+64:33:20.5 |
HIP 44021 |
27.00 |
| 2026-02-23 00:00 |
09:00:46.45 |
+64:33:05.5 |
HIP 44021 |
23.48 |
| 2026-02-23 12:00 |
09:00:08.32 |
+64:32:48.5 |
HIP 44021 |
20.19 |
| 2026-02-24 00:00 |
08:59:30.39 |
+64:32:29.5 |
HIP 44021 |
17.24 |