| Parameter |
Value |
| Designation |
C/2013 B2 (Catalina) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2013-07-01T12:27:38.249280Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:30Z |
| Obs used |
136 |
| NEO |
- |
| M1 |
13.100 |
| K1 |
5.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2013-05-16.0000000 |
| e |
1.00270297 |
| q (au) |
3.734135 |
| a (au) |
-1381.494777 |
| i (deg) |
43.454890 |
| Ω (om, deg) |
331.958789 |
| ω (w, deg) |
156.433585 |
| M (ma, deg) |
-0.000893 |
Magnitude
Scatter + Global Linear
$$
M_a = (6.637 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
6.637 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| 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 |
18:03:34.69 |
-62:36:50.4 |
HIP 88311 |
14.18 |
| 2026-09-20 12:00 |
18:03:35.14 |
-62:36:08.6 |
HIP 88311 |
13.74 |
| 2026-09-21 00:00 |
18:03:35.66 |
-62:35:26.9 |
HIP 88311 |
13.33 |
| 2026-09-21 12:00 |
18:03:36.26 |
-62:34:45.1 |
HIP 88311 |
12.95 |
| 2026-09-22 00:00 |
18:03:36.93 |
-62:34:03.4 |
HIP 88311 |
12.60 |
| 2026-09-22 12:00 |
18:03:37.68 |
-62:33:21.7 |
HIP 88311 |
12.29 |
| 2026-09-23 00:00 |
18:03:38.51 |
-62:32:40.0 |
HIP 88311 |
12.02 |
| 2026-09-23 12:00 |
18:03:39.42 |
-62:31:58.3 |
HIP 88311 |
11.80 |
| 2026-09-24 00:00 |
18:03:40.40 |
-62:31:16.7 |
HIP 88311 |
11.62 |
| 2026-09-24 12:00 |
18:03:41.45 |
-62:30:35.0 |
HIP 88311 |
11.49 |
| 2026-09-25 00:00 |
18:03:42.59 |
-62:29:53.4 |
HIP 88311 |
11.42 |
| 2026-09-25 12:00 |
18:03:43.79 |
-62:29:11.8 |
HIP 88311 |
11.39 |
| 2026-09-26 00:00 |
18:03:45.08 |
-62:28:30.3 |
HIP 88311 |
11.42 |
| 2026-09-26 12:00 |
18:03:46.44 |
-62:27:48.8 |
HIP 88311 |
11.50 |
| 2026-09-27 00:00 |
18:03:47.87 |
-62:27:07.3 |
HIP 88311 |
11.63 |
| 2026-09-27 12:00 |
18:03:49.38 |
-62:26:25.8 |
HIP 88311 |
11.81 |
| 2026-09-28 00:00 |
18:03:50.97 |
-62:25:44.4 |
HIP 88311 |
12.04 |
| 2026-09-28 12:00 |
18:03:52.62 |
-62:25:03.1 |
HIP 88311 |
12.32 |
| 2026-09-29 00:00 |
18:03:54.36 |
-62:24:21.7 |
HIP 88311 |
12.63 |
| 2026-09-29 12:00 |
18:03:56.16 |
-62:23:40.5 |
HIP 88311 |
12.99 |
| 2026-09-30 00:00 |
18:03:58.05 |
-62:22:59.2 |
HIP 88311 |
13.39 |
| 2026-09-30 12:00 |
18:04:00.00 |
-62:22:18.1 |
HIP 88311 |
13.82 |
| 2026-10-01 00:00 |
18:04:02.03 |
-62:21:37.0 |
HIP 88311 |
14.28 |
| 2026-10-01 12:00 |
18:04:04.14 |
-62:20:55.9 |
HIP 88441 |
13.75 |
| 2026-10-02 00:00 |
18:04:06.31 |
-62:20:14.9 |
HIP 88441 |
13.21 |
| 2026-10-02 12:00 |
18:04:08.56 |
-62:19:34.0 |
HIP 88441 |
12.69 |
| 2026-10-03 00:00 |
18:04:10.89 |
-62:18:53.1 |
HIP 88441 |
12.19 |
| 2026-10-03 12:00 |
18:04:13.28 |
-62:18:12.3 |
HIP 88441 |
11.73 |
| 2026-10-04 00:00 |
18:04:15.75 |
-62:17:31.6 |
HIP 88441 |
11.30 |
| 2026-10-04 12:00 |
18:04:18.30 |
-62:16:50.9 |
HIP 88441 |
10.91 |
| 2026-10-05 00:00 |
18:04:20.91 |
-62:16:10.3 |
HIP 88441 |
10.56 |
| 2026-10-05 12:00 |
18:04:23.60 |
-62:15:29.8 |
HIP 88441 |
10.26 |
| 2026-10-06 00:00 |
18:04:26.36 |
-62:14:49.4 |
HIP 88441 |
10.01 |
| 2026-10-06 12:00 |
18:04:29.19 |
-62:14:09.0 |
HIP 88441 |
9.83 |
| 2026-10-07 00:00 |
18:04:32.10 |
-62:13:28.8 |
HIP 88441 |
9.70 |
| 2026-10-07 12:00 |
18:04:35.07 |
-62:12:48.6 |
HIP 88441 |
9.65 |
| 2026-10-08 00:00 |
18:04:38.12 |
-62:12:08.5 |
HIP 88441 |
9.65 |
| 2026-10-08 12:00 |
18:04:41.24 |
-62:11:28.6 |
HIP 88441 |
9.73 |
| 2026-10-09 00:00 |
18:04:44.43 |
-62:10:48.7 |
HIP 88441 |
9.87 |
| 2026-10-09 12:00 |
18:04:47.69 |
-62:10:08.9 |
HIP 88441 |
10.08 |
| 2026-10-10 00:00 |
18:04:51.01 |
-62:09:29.2 |
HIP 88441 |
10.35 |
| 2026-10-10 12:00 |
18:04:54.41 |
-62:08:49.6 |
HIP 88441 |
10.68 |
| 2026-10-11 00:00 |
18:04:57.88 |
-62:08:10.1 |
HIP 88441 |
11.05 |