| Parameter |
Value |
| Designation |
C/2005 N4 (Catalina) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2005-07-02T14:23:55.170240Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:51Z |
| Obs used |
206 |
| NEO |
- |
| M1 |
14.200 |
| K1 |
10.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2005-07-14.0000000 |
| e |
0.96061201 |
| q (au) |
2.303757 |
| a (au) |
58.488820 |
| i (deg) |
116.630292 |
| Ω (om, deg) |
64.036800 |
| ω (w, deg) |
136.545857 |
| M (ma, deg) |
0.025119 |
Magnitude
Scatter + Global Linear
$$
M_a = (15.381 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
15.381 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.920 |
| 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) |
| 2026-07-29 00:00 |
06:58:40.23 |
-31:50:16.7 |
HIP 33699 |
22.27 |
| 2026-07-29 12:00 |
06:58:43.40 |
-31:50:31.9 |
HIP 33699 |
21.86 |
| 2026-07-30 00:00 |
06:58:46.56 |
-31:50:47.3 |
HIP 33699 |
21.47 |
| 2026-07-30 12:00 |
06:58:49.71 |
-31:51:03.0 |
HIP 33699 |
21.11 |
| 2026-07-31 00:00 |
06:58:52.85 |
-31:51:19.0 |
HIP 33699 |
20.76 |
| 2026-07-31 12:00 |
06:58:55.97 |
-31:51:35.3 |
HIP 33699 |
20.45 |
| 2026-08-01 00:00 |
06:58:59.08 |
-31:51:51.9 |
HIP 33699 |
20.16 |
| 2026-08-01 12:00 |
06:59:02.18 |
-31:52:08.7 |
HIP 33699 |
19.89 |
| 2026-08-02 00:00 |
06:59:05.27 |
-31:52:25.8 |
HIP 33699 |
19.65 |
| 2026-08-02 12:00 |
06:59:08.34 |
-31:52:43.1 |
HIP 33699 |
19.45 |
| 2026-08-03 00:00 |
06:59:11.40 |
-31:53:00.8 |
HIP 33699 |
19.27 |
| 2026-08-03 12:00 |
06:59:14.45 |
-31:53:18.7 |
HIP 33699 |
19.12 |
| 2026-08-04 00:00 |
06:59:17.48 |
-31:53:36.8 |
HIP 33699 |
19.00 |
| 2026-08-04 12:00 |
06:59:20.50 |
-31:53:55.3 |
HIP 33699 |
18.91 |
| 2026-08-05 00:00 |
06:59:23.51 |
-31:54:14.0 |
HIP 33699 |
18.86 |
| 2026-08-05 12:00 |
06:59:26.50 |
-31:54:32.9 |
HIP 33699 |
18.84 |
| 2026-08-06 00:00 |
06:59:29.48 |
-31:54:52.2 |
HIP 33699 |
18.85 |
| 2026-08-06 12:00 |
06:59:32.45 |
-31:55:11.7 |
HIP 33699 |
18.89 |
| 2026-08-07 00:00 |
06:59:35.40 |
-31:55:31.4 |
HIP 33699 |
18.96 |
| 2026-08-07 12:00 |
06:59:38.33 |
-31:55:51.5 |
HIP 33699 |
19.07 |
| 2026-08-08 00:00 |
06:59:41.25 |
-31:56:11.7 |
HIP 33699 |
19.20 |
| 2026-08-08 12:00 |
06:59:44.15 |
-31:56:32.3 |
HIP 33699 |
19.37 |
| 2026-08-09 00:00 |
06:59:47.04 |
-31:56:53.1 |
HIP 33699 |
19.56 |
| 2026-08-09 12:00 |
06:59:49.91 |
-31:57:14.1 |
HIP 33699 |
19.79 |
| 2026-08-10 00:00 |
06:59:52.77 |
-31:57:35.4 |
HIP 33699 |
20.03 |
| 2026-08-10 12:00 |
06:59:55.61 |
-31:57:57.0 |
HIP 33699 |
20.31 |
| 2026-08-11 00:00 |
06:59:58.43 |
-31:58:18.8 |
HIP 33699 |
20.61 |
| 2026-08-11 12:00 |
07:00:01.24 |
-31:58:40.9 |
HIP 33699 |
20.93 |
| 2026-08-12 00:00 |
07:00:04.03 |
-31:59:03.2 |
HIP 33699 |
21.28 |
| 2026-08-12 12:00 |
07:00:06.80 |
-31:59:25.7 |
HIP 33699 |
21.65 |
| 2026-08-13 00:00 |
07:00:09.55 |
-31:59:48.6 |
HIP 33699 |
22.03 |
| 2026-08-13 12:00 |
07:00:12.29 |
-32:00:11.6 |
HIP 33699 |
22.44 |
| 2026-08-14 00:00 |
07:00:15.01 |
-32:00:34.9 |
HIP 33699 |
22.86 |
| 2026-08-14 12:00 |
07:00:17.71 |
-32:00:58.4 |
HIP 33699 |
23.30 |
| 2026-08-15 00:00 |
07:00:20.39 |
-32:01:22.2 |
HIP 33699 |
23.76 |
| 2026-08-15 12:00 |
07:00:23.06 |
-32:01:46.2 |
HIP 33699 |
24.23 |
| 2026-08-16 00:00 |
07:00:25.70 |
-32:02:10.4 |
HIP 33699 |
24.72 |
| 2026-08-16 12:00 |
07:00:28.33 |
-32:02:34.9 |
HIP 33699 |
25.21 |
| 2026-08-17 00:00 |
07:00:30.94 |
-32:02:59.6 |
HIP 33699 |
25.72 |
| 2026-08-17 12:00 |
07:00:33.53 |
-32:03:24.5 |
HIP 33699 |
26.24 |
| 2026-08-18 00:00 |
07:00:36.09 |
-32:03:49.7 |
HIP 33699 |
26.77 |
| 2026-08-18 12:00 |
07:00:38.64 |
-32:04:15.1 |
HIP 33699 |
27.31 |
| 2026-08-19 00:00 |
07:00:41.17 |
-32:04:40.7 |
HIP 33699 |
27.86 |