| Parameter |
Value |
| Designation |
C/2007 M2 (Catalina) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2008-12-08T13:33:39.214080Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:09Z |
| Obs used |
432 |
| NEO |
- |
| M1 |
11.900 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2008-05-25.0000000 |
| e |
0.99933270 |
| q (au) |
3.541046 |
| a (au) |
5306.561037 |
| i (deg) |
80.945662 |
| Ω (om, deg) |
357.282850 |
| ω (w, deg) |
220.668951 |
| M (ma, deg) |
359.999496 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.582 + 2.142\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.582 |
| n |
2.142 |
| gf |
0.998 |
| gb |
-0.776 |
| 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) |
| 2026-03-26 00:00 |
23:47:27.58 |
+02:12:04.7 |
HIP 117445 |
20.45 |
| 2026-03-26 12:00 |
23:47:30.57 |
+02:12:28.7 |
HIP 117445 |
19.69 |
| 2026-03-27 00:00 |
23:47:33.56 |
+02:12:52.7 |
HIP 117445 |
18.94 |
| 2026-03-27 12:00 |
23:47:36.54 |
+02:13:16.6 |
HIP 117445 |
18.20 |
| 2026-03-28 00:00 |
23:47:39.51 |
+02:13:40.6 |
HIP 117445 |
17.47 |
| 2026-03-28 12:00 |
23:47:42.49 |
+02:14:04.6 |
HIP 117445 |
16.75 |
| 2026-03-29 00:00 |
23:47:45.45 |
+02:14:28.6 |
HIP 117445 |
16.05 |
| 2026-03-29 12:00 |
23:47:48.41 |
+02:14:52.5 |
HIP 117445 |
15.36 |
| 2026-03-30 00:00 |
23:47:51.37 |
+02:15:16.5 |
HIP 117445 |
14.69 |
| 2026-03-30 12:00 |
23:47:54.32 |
+02:15:40.4 |
HIP 117445 |
14.03 |
| 2026-03-31 00:00 |
23:47:57.26 |
+02:16:04.3 |
HIP 117445 |
13.40 |
| 2026-03-31 12:00 |
23:48:00.20 |
+02:16:28.2 |
HIP 117445 |
12.80 |
| 2026-04-01 00:00 |
23:48:03.13 |
+02:16:52.1 |
HIP 117445 |
12.22 |
| 2026-04-01 12:00 |
23:48:06.06 |
+02:17:16.0 |
HIP 117445 |
11.68 |
| 2026-04-02 00:00 |
23:48:08.97 |
+02:17:39.8 |
HIP 117445 |
11.17 |
| 2026-04-02 12:00 |
23:48:11.89 |
+02:18:03.7 |
HIP 117445 |
10.70 |
| 2026-04-03 00:00 |
23:48:14.79 |
+02:18:27.5 |
HIP 117445 |
10.29 |
| 2026-04-03 12:00 |
23:48:17.69 |
+02:18:51.3 |
HIP 117445 |
9.92 |
| 2026-04-04 00:00 |
23:48:20.58 |
+02:19:15.1 |
HIP 117445 |
9.61 |
| 2026-04-04 12:00 |
23:48:23.46 |
+02:19:38.8 |
HIP 117445 |
9.37 |
| 2026-04-05 00:00 |
23:48:26.33 |
+02:20:02.5 |
HIP 117445 |
9.19 |
| 2026-04-05 12:00 |
23:48:29.20 |
+02:20:26.2 |
HIP 117445 |
9.09 |
| 2026-04-06 00:00 |
23:48:32.06 |
+02:20:49.9 |
HIP 117445 |
9.06 |
| 2026-04-06 12:00 |
23:48:34.91 |
+02:21:13.5 |
HIP 117445 |
9.10 |
| 2026-04-07 00:00 |
23:48:37.75 |
+02:21:37.2 |
HIP 117473 |
8.93 |
| 2026-04-07 12:00 |
23:48:40.58 |
+02:22:00.7 |
HIP 117473 |
8.14 |
| 2026-04-08 00:00 |
23:48:43.40 |
+02:22:24.3 |
HIP 117473 |
7.36 |
| 2026-04-08 12:00 |
23:48:46.22 |
+02:22:47.8 |
HIP 117473 |
6.58 |
| 2026-04-09 00:00 |
23:48:49.02 |
+02:23:11.3 |
HIP 117473 |
5.82 |
| 2026-04-09 12:00 |
23:48:51.82 |
+02:23:34.7 |
HIP 117473 |
5.07 |
| 2026-04-10 00:00 |
23:48:54.60 |
+02:23:58.1 |
HIP 117473 |
4.34 |
| 2026-04-10 12:00 |
23:48:57.38 |
+02:24:21.5 |
HIP 117473 |
3.64 |
| 2026-04-11 00:00 |
23:49:00.14 |
+02:24:44.8 |
HIP 117473 |
3.00 |
| 2026-04-11 12:00 |
23:49:02.90 |
+02:25:08.1 |
HIP 117473 |
2.44 |
| 2026-04-12 00:00 |
23:49:05.64 |
+02:25:31.3 |
HIP 117473 |
2.05 |
| 2026-04-12 12:00 |
23:49:08.38 |
+02:25:54.5 |
HIP 117473 |
1.91 |
| 2026-04-13 00:00 |
23:49:11.10 |
+02:26:17.7 |
HIP 117473 |
2.09 |
| 2026-04-13 12:00 |
23:49:13.81 |
+02:26:40.8 |
HIP 117473 |
2.51 |
| 2026-04-14 00:00 |
23:49:16.51 |
+02:27:03.8 |
HIP 117473 |
3.07 |
| 2026-04-14 12:00 |
23:49:19.20 |
+02:27:26.8 |
HIP 117473 |
3.71 |
| 2026-04-15 00:00 |
23:49:21.88 |
+02:27:49.8 |
HIP 117473 |
4.38 |
| 2026-04-15 12:00 |
23:49:24.55 |
+02:28:12.7 |
HIP 117473 |
5.09 |
| 2026-04-16 00:00 |
23:49:27.20 |
+02:28:35.5 |
HIP 117473 |
5.80 |