| 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) |
| 2026-05-12 00:00 |
23:51:24.23 |
+02:46:38.2 |
HIP 117683 |
12.44 |
| 2026-05-12 12:00 |
23:51:26.00 |
+02:46:56.5 |
HIP 117683 |
11.92 |
| 2026-05-13 00:00 |
23:51:27.76 |
+02:47:14.7 |
HIP 117683 |
11.40 |
| 2026-05-13 12:00 |
23:51:29.49 |
+02:47:32.7 |
HIP 117683 |
10.89 |
| 2026-05-14 00:00 |
23:51:31.20 |
+02:47:50.7 |
HIP 117683 |
10.39 |
| 2026-05-14 12:00 |
23:51:32.90 |
+02:48:08.5 |
HIP 117683 |
9.89 |
| 2026-05-15 00:00 |
23:51:34.57 |
+02:48:26.2 |
HIP 117683 |
9.40 |
| 2026-05-15 12:00 |
23:51:36.22 |
+02:48:43.7 |
HIP 117683 |
8.92 |
| 2026-05-16 00:00 |
23:51:37.84 |
+02:49:01.2 |
HIP 117683 |
8.44 |
| 2026-05-16 12:00 |
23:51:39.45 |
+02:49:18.5 |
HIP 117683 |
7.97 |
| 2026-05-17 00:00 |
23:51:41.03 |
+02:49:35.7 |
HIP 117683 |
7.51 |
| 2026-05-17 12:00 |
23:51:42.60 |
+02:49:52.8 |
HIP 117683 |
7.06 |
| 2026-05-18 00:00 |
23:51:44.14 |
+02:50:09.8 |
HIP 117683 |
6.61 |
| 2026-05-18 12:00 |
23:51:45.66 |
+02:50:26.6 |
HIP 117683 |
6.18 |
| 2026-05-19 00:00 |
23:51:47.16 |
+02:50:43.3 |
HIP 117683 |
5.76 |
| 2026-05-19 12:00 |
23:51:48.63 |
+02:50:59.9 |
HIP 117683 |
5.35 |
| 2026-05-20 00:00 |
23:51:50.08 |
+02:51:16.3 |
HIP 117683 |
4.95 |
| 2026-05-20 12:00 |
23:51:51.51 |
+02:51:32.6 |
HIP 117683 |
4.56 |
| 2026-05-21 00:00 |
23:51:52.92 |
+02:51:48.8 |
HIP 117683 |
4.20 |
| 2026-05-21 12:00 |
23:51:54.30 |
+02:52:04.8 |
HIP 117683 |
3.85 |
| 2026-05-22 00:00 |
23:51:55.67 |
+02:52:20.8 |
HIP 117683 |
3.52 |
| 2026-05-22 12:00 |
23:51:57.00 |
+02:52:36.5 |
HIP 117683 |
3.22 |
| 2026-05-23 00:00 |
23:51:58.32 |
+02:52:52.2 |
HIP 117683 |
2.96 |
| 2026-05-23 12:00 |
23:51:59.61 |
+02:53:07.7 |
HIP 117683 |
2.73 |
| 2026-05-24 00:00 |
23:52:00.88 |
+02:53:23.1 |
HIP 117683 |
2.56 |
| 2026-05-24 12:00 |
23:52:02.13 |
+02:53:38.3 |
HIP 117683 |
2.44 |
| 2026-05-25 00:00 |
23:52:03.35 |
+02:53:53.4 |
HIP 117683 |
2.38 |
| 2026-05-25 12:00 |
23:52:04.55 |
+02:54:08.4 |
HIP 117683 |
2.38 |
| 2026-05-26 00:00 |
23:52:05.73 |
+02:54:23.2 |
HIP 117683 |
2.44 |
| 2026-05-26 12:00 |
23:52:06.88 |
+02:54:37.9 |
HIP 117683 |
2.56 |
| 2026-05-27 00:00 |
23:52:08.01 |
+02:54:52.5 |
HIP 117683 |
2.71 |
| 2026-05-27 12:00 |
23:52:09.12 |
+02:55:06.9 |
HIP 117683 |
2.91 |
| 2026-05-28 00:00 |
23:52:10.20 |
+02:55:21.1 |
HIP 117683 |
3.12 |
| 2026-05-28 12:00 |
23:52:11.26 |
+02:55:35.3 |
HIP 117683 |
3.36 |
| 2026-05-29 00:00 |
23:52:12.29 |
+02:55:49.2 |
HIP 117683 |
3.61 |
| 2026-05-29 12:00 |
23:52:13.30 |
+02:56:03.1 |
HIP 117683 |
3.87 |
| 2026-05-30 00:00 |
23:52:14.29 |
+02:56:16.8 |
HIP 117683 |
4.13 |
| 2026-05-30 12:00 |
23:52:15.25 |
+02:56:30.3 |
HIP 117683 |
4.40 |
| 2026-05-31 00:00 |
23:52:16.19 |
+02:56:43.7 |
HIP 117683 |
4.67 |
| 2026-05-31 12:00 |
23:52:17.10 |
+02:56:57.0 |
HIP 117683 |
4.94 |
| 2026-06-01 00:00 |
23:52:17.99 |
+02:57:10.1 |
HIP 117683 |
5.21 |
| 2026-06-01 12:00 |
23:52:18.86 |
+02:57:23.1 |
HIP 117683 |
5.48 |
| 2026-06-02 00:00 |
23:52:19.70 |
+02:57:35.9 |
HIP 117683 |
5.74 |