| Parameter |
Value |
| Designation |
C/2021 K3 (Catalina) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2022-02-02T08:11:00.119040Z |
| Orbit solution date (soln_date, UTC) |
2022-06-07T21:45:11Z |
| Obs used |
99 |
| NEO |
- |
| M1 |
14.500 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2021-07-16.0000000 |
| e |
1.00356145 |
| q (au) |
5.230100 |
| a (au) |
-1468.531415 |
| i (deg) |
134.804408 |
| Ω (om, deg) |
114.441510 |
| ω (w, deg) |
181.948465 |
| M (ma, deg) |
-0.003526 |
Magnitude
Scatter + Global Linear
$$
M_a = (17.424 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
17.424 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.757 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
10:51:27.88 |
-45:21:33.3 |
HIP 52963 |
21.74 |
| 2026-05-12 12:00 |
10:51:20.48 |
-45:18:53.5 |
HIP 52963 |
22.76 |
| 2026-05-13 00:00 |
10:51:13.20 |
-45:16:13.7 |
HIP 52963 |
24.11 |
| 2026-05-13 12:00 |
10:51:06.06 |
-45:13:34.0 |
HIP 52963 |
25.73 |
| 2026-05-14 00:00 |
10:50:59.04 |
-45:10:54.5 |
HIP 52866 |
25.26 |
| 2026-05-14 12:00 |
10:50:52.16 |
-45:08:15.0 |
HIP 52866 |
25.04 |
| 2026-05-15 00:00 |
10:50:45.40 |
-45:05:35.7 |
HIP 52866 |
25.19 |
| 2026-05-15 12:00 |
10:50:38.77 |
-45:02:56.6 |
HIP 52866 |
25.67 |
| 2026-05-16 00:00 |
10:50:32.28 |
-45:00:17.6 |
HIP 52866 |
26.48 |
| 2026-05-16 12:00 |
10:50:25.91 |
-44:57:38.8 |
HIP 52866 |
27.59 |
| 2026-05-17 00:00 |
10:50:19.66 |
-44:55:00.1 |
HIP 52866 |
28.94 |
| 2026-05-17 12:00 |
10:50:13.55 |
-44:52:21.7 |
HIP 52866 |
30.52 |
| 2026-05-18 00:00 |
10:50:07.57 |
-44:49:43.4 |
HIP 53199 |
31.16 |
| 2026-05-18 12:00 |
10:50:01.71 |
-44:47:05.4 |
HIP 52855 |
29.42 |
| 2026-05-19 00:00 |
10:49:55.98 |
-44:44:27.6 |
HIP 52855 |
26.68 |
| 2026-05-19 12:00 |
10:49:50.38 |
-44:41:50.1 |
HIP 52855 |
23.98 |
| 2026-05-20 00:00 |
10:49:44.91 |
-44:39:12.8 |
HIP 52855 |
21.32 |
| 2026-05-20 12:00 |
10:49:39.56 |
-44:36:35.8 |
HIP 52855 |
18.71 |
| 2026-05-21 00:00 |
10:49:34.34 |
-44:33:59.0 |
HIP 52855 |
16.19 |
| 2026-05-21 12:00 |
10:49:29.24 |
-44:31:22.6 |
HIP 52855 |
13.78 |
| 2026-05-22 00:00 |
10:49:24.27 |
-44:28:46.4 |
HIP 52855 |
11.55 |
| 2026-05-22 12:00 |
10:49:19.43 |
-44:26:10.6 |
HIP 52927 |
9.20 |
| 2026-05-23 00:00 |
10:49:14.71 |
-44:23:35.1 |
HIP 52927 |
6.89 |
| 2026-05-23 12:00 |
10:49:10.11 |
-44:21:00.0 |
HIP 52927 |
5.01 |
| 2026-05-24 00:00 |
10:49:05.64 |
-44:18:25.1 |
HIP 52927 |
4.16 |
| 2026-05-24 12:00 |
10:49:01.29 |
-44:15:50.6 |
HIP 52927 |
4.89 |
| 2026-05-25 00:00 |
10:48:57.06 |
-44:13:16.5 |
HIP 52927 |
6.68 |
| 2026-05-25 12:00 |
10:48:52.96 |
-44:10:42.8 |
HIP 52927 |
8.91 |
| 2026-05-26 00:00 |
10:48:48.98 |
-44:08:09.4 |
HIP 52927 |
11.31 |
| 2026-05-26 12:00 |
10:48:45.12 |
-44:05:36.5 |
HIP 52927 |
13.79 |
| 2026-05-27 00:00 |
10:48:41.38 |
-44:03:03.9 |
HIP 52927 |
16.30 |
| 2026-05-27 12:00 |
10:48:37.76 |
-44:00:31.8 |
HIP 52927 |
18.83 |
| 2026-05-28 00:00 |
10:48:34.26 |
-43:58:00.0 |
HIP 52927 |
21.36 |
| 2026-05-28 12:00 |
10:48:30.88 |
-43:55:28.7 |
HIP 52927 |
23.90 |
| 2026-05-29 00:00 |
10:48:27.62 |
-43:52:57.9 |
HIP 52811 |
25.93 |
| 2026-05-29 12:00 |
10:48:24.48 |
-43:50:27.5 |
HIP 52811 |
23.37 |
| 2026-05-30 00:00 |
10:48:21.46 |
-43:47:57.5 |
HIP 52811 |
20.82 |
| 2026-05-30 12:00 |
10:48:18.55 |
-43:45:28.0 |
HIP 52811 |
18.28 |
| 2026-05-31 00:00 |
10:48:15.76 |
-43:42:59.0 |
HIP 52811 |
15.77 |
| 2026-05-31 12:00 |
10:48:13.09 |
-43:40:30.5 |
HIP 52811 |
13.27 |
| 2026-06-01 00:00 |
10:48:10.54 |
-43:38:02.4 |
HIP 52811 |
10.80 |
| 2026-06-01 12:00 |
10:48:08.10 |
-43:35:34.9 |
HIP 52811 |
8.37 |
| 2026-06-02 00:00 |
10:48:05.77 |
-43:33:07.8 |
HIP 52811 |
6.02 |