| 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) |
| 2026-05-12 00:00 |
18:30:45.29 |
-63:32:16.1 |
HIP 90501 |
22.59 |
| 2026-05-12 12:00 |
18:30:39.43 |
-63:32:45.4 |
HIP 90501 |
22.37 |
| 2026-05-13 00:00 |
18:30:33.51 |
-63:33:14.4 |
HIP 90501 |
22.16 |
| 2026-05-13 12:00 |
18:30:27.52 |
-63:33:43.2 |
HIP 90501 |
21.98 |
| 2026-05-14 00:00 |
18:30:21.47 |
-63:34:11.8 |
HIP 90501 |
21.82 |
| 2026-05-14 12:00 |
18:30:15.36 |
-63:34:40.1 |
HIP 90501 |
21.69 |
| 2026-05-15 00:00 |
18:30:09.19 |
-63:35:08.1 |
HIP 90501 |
21.57 |
| 2026-05-15 12:00 |
18:30:02.95 |
-63:35:35.9 |
HIP 90501 |
21.48 |
| 2026-05-16 00:00 |
18:29:56.66 |
-63:36:03.4 |
HIP 90501 |
21.42 |
| 2026-05-16 12:00 |
18:29:50.30 |
-63:36:30.7 |
HIP 90501 |
21.38 |
| 2026-05-17 00:00 |
18:29:43.88 |
-63:36:57.7 |
HIP 90501 |
21.37 |
| 2026-05-17 12:00 |
18:29:37.41 |
-63:37:24.4 |
HIP 90501 |
21.39 |
| 2026-05-18 00:00 |
18:29:30.88 |
-63:37:50.9 |
HIP 90501 |
21.43 |
| 2026-05-18 12:00 |
18:29:24.28 |
-63:38:17.0 |
HIP 90501 |
21.50 |
| 2026-05-19 00:00 |
18:29:17.64 |
-63:38:42.9 |
HIP 90501 |
21.59 |
| 2026-05-19 12:00 |
18:29:10.93 |
-63:39:08.5 |
HIP 90501 |
21.71 |
| 2026-05-20 00:00 |
18:29:04.17 |
-63:39:33.9 |
HIP 90501 |
21.86 |
| 2026-05-20 12:00 |
18:28:57.36 |
-63:39:58.9 |
HIP 90501 |
22.04 |
| 2026-05-21 00:00 |
18:28:50.49 |
-63:40:23.6 |
HIP 90501 |
22.24 |
| 2026-05-21 12:00 |
18:28:43.56 |
-63:40:48.1 |
HIP 90501 |
22.47 |
| 2026-05-22 00:00 |
18:28:36.58 |
-63:41:12.3 |
HIP 90501 |
22.73 |
| 2026-05-22 12:00 |
18:28:29.55 |
-63:41:36.1 |
HIP 90501 |
23.00 |
| 2026-05-23 00:00 |
18:28:22.47 |
-63:41:59.7 |
HIP 90501 |
23.31 |
| 2026-05-23 12:00 |
18:28:15.34 |
-63:42:22.9 |
HIP 90501 |
23.64 |
| 2026-05-24 00:00 |
18:28:08.16 |
-63:42:45.9 |
HIP 90501 |
23.99 |
| 2026-05-24 12:00 |
18:28:00.92 |
-63:43:08.5 |
HIP 90501 |
24.36 |
| 2026-05-25 00:00 |
18:27:53.64 |
-63:43:30.9 |
HIP 90501 |
24.75 |
| 2026-05-25 12:00 |
18:27:46.31 |
-63:43:52.9 |
HIP 90501 |
25.17 |
| 2026-05-26 00:00 |
18:27:38.93 |
-63:44:14.6 |
HIP 90501 |
25.60 |
| 2026-05-26 12:00 |
18:27:31.51 |
-63:44:36.0 |
HIP 90501 |
26.06 |
| 2026-05-27 00:00 |
18:27:24.03 |
-63:44:57.1 |
HIP 90501 |
26.53 |
| 2026-05-27 12:00 |
18:27:16.52 |
-63:45:17.9 |
HIP 90501 |
27.02 |
| 2026-05-28 00:00 |
18:27:08.95 |
-63:45:38.3 |
HIP 90501 |
27.53 |
| 2026-05-28 12:00 |
18:27:01.35 |
-63:45:58.4 |
HIP 90501 |
28.05 |
| 2026-05-29 00:00 |
18:26:53.69 |
-63:46:18.2 |
HIP 90501 |
28.59 |
| 2026-05-29 12:00 |
18:26:46.00 |
-63:46:37.7 |
HIP 90501 |
29.14 |
| 2026-05-30 00:00 |
18:26:38.26 |
-63:46:56.8 |
HIP 90501 |
29.71 |
| 2026-05-30 12:00 |
18:26:30.48 |
-63:47:15.6 |
HIP 90155 |
29.81 |
| 2026-05-31 00:00 |
18:26:22.66 |
-63:47:34.1 |
HIP 90155 |
29.56 |
| 2026-05-31 12:00 |
18:26:14.80 |
-63:47:52.2 |
HIP 90155 |
29.33 |
| 2026-06-01 00:00 |
18:26:06.90 |
-63:48:10.0 |
HIP 90155 |
29.12 |
| 2026-06-01 12:00 |
18:25:58.96 |
-63:48:27.5 |
HIP 90155 |
28.94 |
| 2026-06-02 00:00 |
18:25:50.99 |
-63:48:44.6 |
HIP 90155 |
28.77 |