| Parameter |
Value |
| Designation |
C/2004 K1 (Catalina) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2005-07-05T02:28:32.972160Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:41Z |
| Obs used |
1117 |
| NEO |
- |
| M1 |
7.900 |
| K1 |
11.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2005-05-10.0000000 |
| e |
0.99813226 |
| q (au) |
3.399147 |
| a (au) |
1819.922556 |
| i (deg) |
153.747520 |
| Ω (om, deg) |
326.923197 |
| ω (w, deg) |
97.751687 |
| M (ma, deg) |
359.999288 |
Magnitude
Scatter + Global Linear
$$
M_a = (8.179 + 3.575\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
8.179 |
| n |
3.575 |
| gf |
0.998 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
05:49:37.35 |
-00:00:14.5 |
HIP 27507 |
3.67 |
| 2026-09-20 12:00 |
05:49:37.14 |
-00:00:32.9 |
HIP 27507 |
3.91 |
| 2026-09-21 00:00 |
05:49:36.89 |
-00:00:51.2 |
HIP 27507 |
4.15 |
| 2026-09-21 12:00 |
05:49:36.63 |
-00:01:09.5 |
HIP 27507 |
4.40 |
| 2026-09-22 00:00 |
05:49:36.33 |
-00:01:27.9 |
HIP 27507 |
4.65 |
| 2026-09-22 12:00 |
05:49:36.02 |
-00:01:46.3 |
HIP 27507 |
4.91 |
| 2026-09-23 00:00 |
05:49:35.67 |
-00:02:04.6 |
HIP 27507 |
5.18 |
| 2026-09-23 12:00 |
05:49:35.31 |
-00:02:23.0 |
HIP 27507 |
5.44 |
| 2026-09-24 00:00 |
05:49:34.91 |
-00:02:41.4 |
HIP 27507 |
5.72 |
| 2026-09-24 12:00 |
05:49:34.49 |
-00:02:59.8 |
HIP 27507 |
5.99 |
| 2026-09-25 00:00 |
05:49:34.05 |
-00:03:18.2 |
HIP 27507 |
6.27 |
| 2026-09-25 12:00 |
05:49:33.58 |
-00:03:36.5 |
HIP 27507 |
6.55 |
| 2026-09-26 00:00 |
05:49:33.08 |
-00:03:54.9 |
HIP 27507 |
6.84 |
| 2026-09-26 12:00 |
05:49:32.56 |
-00:04:13.3 |
HIP 27507 |
7.13 |
| 2026-09-27 00:00 |
05:49:32.02 |
-00:04:31.7 |
HIP 27507 |
7.42 |
| 2026-09-27 12:00 |
05:49:31.45 |
-00:04:50.1 |
HIP 27507 |
7.71 |
| 2026-09-28 00:00 |
05:49:30.85 |
-00:05:08.5 |
HIP 27507 |
8.01 |
| 2026-09-28 12:00 |
05:49:30.23 |
-00:05:26.8 |
HIP 27536 |
8.08 |
| 2026-09-29 00:00 |
05:49:29.58 |
-00:05:45.2 |
HIP 27536 |
8.00 |
| 2026-09-29 12:00 |
05:49:28.91 |
-00:06:03.5 |
HIP 27536 |
7.93 |
| 2026-09-30 00:00 |
05:49:28.21 |
-00:06:21.9 |
HIP 27536 |
7.88 |
| 2026-09-30 12:00 |
05:49:27.49 |
-00:06:40.2 |
HIP 27536 |
7.86 |
| 2026-10-01 00:00 |
05:49:26.74 |
-00:06:58.5 |
HIP 27536 |
7.85 |
| 2026-10-01 12:00 |
05:49:25.97 |
-00:07:16.9 |
HIP 27536 |
7.87 |
| 2026-10-02 00:00 |
05:49:25.17 |
-00:07:35.1 |
HIP 27536 |
7.91 |
| 2026-10-02 12:00 |
05:49:24.35 |
-00:07:53.4 |
HIP 27536 |
7.97 |
| 2026-10-03 00:00 |
05:49:23.50 |
-00:08:11.7 |
HIP 27536 |
8.05 |
| 2026-10-03 12:00 |
05:49:22.62 |
-00:08:29.9 |
HIP 27536 |
8.16 |
| 2026-10-04 00:00 |
05:49:21.72 |
-00:08:48.1 |
HIP 27536 |
8.29 |
| 2026-10-04 12:00 |
05:49:20.80 |
-00:09:06.3 |
HIP 27536 |
8.44 |
| 2026-10-05 00:00 |
05:49:19.85 |
-00:09:24.5 |
HIP 27536 |
8.61 |
| 2026-10-05 12:00 |
05:49:18.87 |
-00:09:42.7 |
HIP 27536 |
8.80 |
| 2026-10-06 00:00 |
05:49:17.87 |
-00:10:00.8 |
HIP 27536 |
9.01 |
| 2026-10-06 12:00 |
05:49:16.84 |
-00:10:18.9 |
HIP 27536 |
9.23 |
| 2026-10-07 00:00 |
05:49:15.79 |
-00:10:37.0 |
HIP 27536 |
9.48 |
| 2026-10-07 12:00 |
05:49:14.72 |
-00:10:55.0 |
HIP 27536 |
9.74 |
| 2026-10-08 00:00 |
05:49:13.62 |
-00:11:13.0 |
HIP 27536 |
10.02 |
| 2026-10-08 12:00 |
05:49:12.49 |
-00:11:31.0 |
HIP 27536 |
10.31 |
| 2026-10-09 00:00 |
05:49:11.34 |
-00:11:48.9 |
HIP 27536 |
10.61 |
| 2026-10-09 12:00 |
05:49:10.16 |
-00:12:06.8 |
HIP 27536 |
10.93 |
| 2026-10-10 00:00 |
05:49:08.96 |
-00:12:24.7 |
HIP 27536 |
11.27 |
| 2026-10-10 12:00 |
05:49:07.73 |
-00:12:42.5 |
HIP 27536 |
11.61 |
| 2026-10-11 00:00 |
05:49:06.48 |
-00:13:00.3 |
HIP 27536 |
11.97 |