| Parameter |
Value |
| Designation |
299P/Catalina-PANSTARRS |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2024-04-30T20:48:54.460800Z |
| Orbit solution date (soln_date, UTC) |
2026-09-15T13:42:29Z |
| Obs used |
905 |
| NEO |
- |
| M1 |
6.800 |
| K1 |
17.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2021-05-09.0000000 |
| e |
0.28150261 |
| q (au) |
3.150713 |
| a (au) |
4.385142 |
| i (deg) |
10.474640 |
| Ω (om, deg) |
271.625699 |
| ω (w, deg) |
323.888501 |
| M (ma, deg) |
243.237187 |
Magnitude
Scatter + Global Linear
$$
M_a = (7.310 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
7.310 |
| n |
6.000 |
| gf |
0.994 |
| gb |
-1.000 |
| k |
1.000 |
| δ90 |
1.000 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2022-02-05 |
2024-04-22 |
+4.3053 |
-1.815 |
| 2024-05-02 |
2025-09-19 |
+24.4776 |
-13.053 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
23:36:06.96 |
+11:48:50.9 |
HIP 116627 |
38.99 |
| 2026-09-20 12:00 |
23:35:50.19 |
+11:47:02.9 |
HIP 116627 |
40.99 |
| 2026-09-21 00:00 |
23:35:33.46 |
+11:45:14.1 |
HIP 116325 |
40.06 |
| 2026-09-21 12:00 |
23:35:16.76 |
+11:43:24.3 |
HIP 116325 |
36.48 |
| 2026-09-22 00:00 |
23:35:00.09 |
+11:41:33.8 |
HIP 116325 |
33.11 |
| 2026-09-22 12:00 |
23:34:43.46 |
+11:39:42.4 |
HIP 116325 |
30.03 |
| 2026-09-23 00:00 |
23:34:26.87 |
+11:37:50.2 |
HIP 116325 |
27.32 |
| 2026-09-23 12:00 |
23:34:10.32 |
+11:35:57.2 |
HIP 116325 |
25.10 |
| 2026-09-24 00:00 |
23:33:53.82 |
+11:34:03.5 |
HIP 116325 |
23.53 |
| 2026-09-24 12:00 |
23:33:37.37 |
+11:32:09.1 |
HIP 116156 |
21.98 |
| 2026-09-25 00:00 |
23:33:20.97 |
+11:30:13.9 |
HIP 116156 |
17.95 |
| 2026-09-25 12:00 |
23:33:04.63 |
+11:28:18.1 |
HIP 116156 |
14.19 |
| 2026-09-26 00:00 |
23:32:48.34 |
+11:26:21.5 |
HIP 116156 |
10.96 |
| 2026-09-26 12:00 |
23:32:32.12 |
+11:24:24.3 |
HIP 116156 |
8.87 |
| 2026-09-27 00:00 |
23:32:15.95 |
+11:22:26.5 |
HIP 116156 |
8.76 |
| 2026-09-27 12:00 |
23:31:59.86 |
+11:20:28.1 |
HIP 116156 |
10.68 |
| 2026-09-28 00:00 |
23:31:43.83 |
+11:18:29.1 |
HIP 116156 |
13.80 |
| 2026-09-28 12:00 |
23:31:27.88 |
+11:16:29.5 |
HIP 116156 |
17.47 |
| 2026-09-29 00:00 |
23:31:12.00 |
+11:14:29.4 |
HIP 116156 |
21.41 |
| 2026-09-29 12:00 |
23:30:56.19 |
+11:12:28.8 |
HIP 116087 |
20.31 |
| 2026-09-30 00:00 |
23:30:40.47 |
+11:10:27.7 |
HIP 116087 |
20.03 |
| 2026-09-30 12:00 |
23:30:24.83 |
+11:08:26.0 |
HIP 116087 |
20.66 |
| 2026-10-01 00:00 |
23:30:09.27 |
+11:06:24.0 |
HIP 116087 |
22.12 |
| 2026-10-01 12:00 |
23:29:53.80 |
+11:04:21.4 |
HIP 116087 |
24.25 |
| 2026-10-02 00:00 |
23:29:38.42 |
+11:02:18.5 |
HIP 115825 |
25.78 |
| 2026-10-02 12:00 |
23:29:23.14 |
+11:00:15.2 |
HIP 115825 |
22.78 |
| 2026-10-03 00:00 |
23:29:07.95 |
+10:58:11.5 |
HIP 115825 |
20.26 |
| 2026-10-03 12:00 |
23:28:52.86 |
+10:56:07.4 |
HIP 115825 |
18.41 |
| 2026-10-04 00:00 |
23:28:37.87 |
+10:54:03.1 |
HIP 115825 |
17.45 |
| 2026-10-04 12:00 |
23:28:22.98 |
+10:51:58.4 |
HIP 115825 |
17.49 |
| 2026-10-05 00:00 |
23:28:08.20 |
+10:49:53.5 |
HIP 115825 |
18.52 |
| 2026-10-05 12:00 |
23:27:53.53 |
+10:47:48.3 |
HIP 115825 |
20.37 |
| 2026-10-06 00:00 |
23:27:38.97 |
+10:45:42.9 |
HIP 115825 |
22.84 |
| 2026-10-06 12:00 |
23:27:24.53 |
+10:43:37.2 |
HIP 115825 |
25.74 |
| 2026-10-07 00:00 |
23:27:10.20 |
+10:41:31.4 |
HIP 115825 |
28.93 |
| 2026-10-07 12:00 |
23:26:55.99 |
+10:39:25.4 |
HIP 115592 |
30.50 |
| 2026-10-08 00:00 |
23:26:41.91 |
+10:37:19.3 |
HIP 115592 |
27.01 |
| 2026-10-08 12:00 |
23:26:27.95 |
+10:35:13.1 |
HIP 115592 |
23.73 |
| 2026-10-09 00:00 |
23:26:14.11 |
+10:33:06.8 |
HIP 115592 |
20.73 |
| 2026-10-09 12:00 |
23:26:00.41 |
+10:31:00.5 |
HIP 115592 |
18.17 |
| 2026-10-10 00:00 |
23:25:46.83 |
+10:28:54.1 |
HIP 115592 |
16.20 |
| 2026-10-10 12:00 |
23:25:33.40 |
+10:26:47.7 |
HIP 115592 |
15.06 |
| 2026-10-11 00:00 |
23:25:20.09 |
+10:24:41.3 |
HIP 115592 |
14.90 |