| 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 |
1.000 |
| 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) |
| 2026-09-25 00:00 |
23:45:34.98 |
+02:39:04.0 |
HIP 117319 |
29.81 |
| 2026-09-25 12:00 |
23:45:31.75 |
+02:38:46.9 |
HIP 117319 |
30.66 |
| 2026-09-26 00:00 |
23:45:28.53 |
+02:38:29.8 |
HIP 117319 |
31.50 |
| 2026-09-26 12:00 |
23:45:25.31 |
+02:38:12.7 |
HIP 117319 |
32.34 |
| 2026-09-27 00:00 |
23:45:22.09 |
+02:37:55.6 |
HIP 117156 |
32.75 |
| 2026-09-27 12:00 |
23:45:18.88 |
+02:37:38.5 |
HIP 117156 |
32.36 |
| 2026-09-28 00:00 |
23:45:15.67 |
+02:37:21.4 |
HIP 117156 |
32.00 |
| 2026-09-28 12:00 |
23:45:12.47 |
+02:37:04.3 |
HIP 117156 |
31.65 |
| 2026-09-29 00:00 |
23:45:09.27 |
+02:36:47.2 |
HIP 117156 |
31.33 |
| 2026-09-29 12:00 |
23:45:06.07 |
+02:36:30.0 |
HIP 117156 |
31.02 |
| 2026-09-30 00:00 |
23:45:02.88 |
+02:36:12.9 |
HIP 117084 |
30.52 |
| 2026-09-30 12:00 |
23:44:59.70 |
+02:35:55.8 |
HIP 117084 |
29.92 |
| 2026-10-01 00:00 |
23:44:56.52 |
+02:35:38.7 |
HIP 117084 |
29.34 |
| 2026-10-01 12:00 |
23:44:53.35 |
+02:35:21.6 |
HIP 117084 |
28.76 |
| 2026-10-02 00:00 |
23:44:50.19 |
+02:35:04.5 |
HIP 117084 |
28.21 |
| 2026-10-02 12:00 |
23:44:47.03 |
+02:34:47.4 |
HIP 117084 |
27.66 |
| 2026-10-03 00:00 |
23:44:43.87 |
+02:34:30.3 |
HIP 117084 |
27.14 |
| 2026-10-03 12:00 |
23:44:40.73 |
+02:34:13.2 |
HIP 117084 |
26.63 |
| 2026-10-04 00:00 |
23:44:37.59 |
+02:33:56.2 |
HIP 117084 |
26.13 |
| 2026-10-04 12:00 |
23:44:34.46 |
+02:33:39.1 |
HIP 117084 |
25.66 |
| 2026-10-05 00:00 |
23:44:31.34 |
+02:33:22.1 |
HIP 117084 |
25.20 |
| 2026-10-05 12:00 |
23:44:28.23 |
+02:33:05.1 |
HIP 117084 |
24.77 |
| 2026-10-06 00:00 |
23:44:25.12 |
+02:32:48.1 |
HIP 117084 |
24.35 |
| 2026-10-06 12:00 |
23:44:22.02 |
+02:32:31.2 |
HIP 117084 |
23.96 |
| 2026-10-07 00:00 |
23:44:18.93 |
+02:32:14.2 |
HIP 117084 |
23.59 |
| 2026-10-07 12:00 |
23:44:15.85 |
+02:31:57.3 |
HIP 117084 |
23.25 |
| 2026-10-08 00:00 |
23:44:12.78 |
+02:31:40.4 |
HIP 117084 |
22.93 |
| 2026-10-08 12:00 |
23:44:09.72 |
+02:31:23.5 |
HIP 117084 |
22.63 |
| 2026-10-09 00:00 |
23:44:06.67 |
+02:31:06.7 |
HIP 117084 |
22.36 |
| 2026-10-09 12:00 |
23:44:03.63 |
+02:30:49.9 |
HIP 117084 |
22.12 |
| 2026-10-10 00:00 |
23:44:00.60 |
+02:30:33.2 |
HIP 117084 |
21.90 |
| 2026-10-10 12:00 |
23:43:57.58 |
+02:30:16.4 |
HIP 117084 |
21.72 |
| 2026-10-11 00:00 |
23:43:54.57 |
+02:29:59.7 |
HIP 117084 |
21.56 |
| 2026-10-11 12:00 |
23:43:51.58 |
+02:29:43.1 |
HIP 117084 |
21.43 |
| 2026-10-12 00:00 |
23:43:48.59 |
+02:29:26.5 |
HIP 117084 |
21.33 |
| 2026-10-12 12:00 |
23:43:45.61 |
+02:29:09.9 |
HIP 117084 |
21.26 |
| 2026-10-13 00:00 |
23:43:42.65 |
+02:28:53.4 |
HIP 117084 |
21.21 |
| 2026-10-13 12:00 |
23:43:39.70 |
+02:28:36.9 |
HIP 117084 |
21.20 |
| 2026-10-14 00:00 |
23:43:36.76 |
+02:28:20.5 |
HIP 117084 |
21.22 |
| 2026-10-14 12:00 |
23:43:33.84 |
+02:28:04.1 |
HIP 117084 |
21.26 |
| 2026-10-15 00:00 |
23:43:30.92 |
+02:27:47.8 |
HIP 117084 |
21.33 |
| 2026-10-15 12:00 |
23:43:28.02 |
+02:27:31.5 |
HIP 117084 |
21.43 |
| 2026-10-16 00:00 |
23:43:25.14 |
+02:27:15.3 |
HIP 117084 |
21.56 |