| Parameter |
Value |
| Designation |
C/1999 F1 (Catalina) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2002-02-13T15:14:58.715520Z |
| Orbit solution date (soln_date, UTC) |
2026-06-09T11:12:23Z |
| Obs used |
172 |
| NEO |
- |
| M1 |
6.200 |
| K1 |
7.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2001-04-29.0000000 |
| e |
0.99915402 |
| q (au) |
5.787032 |
| a (au) |
6840.659124 |
| i (deg) |
92.036105 |
| Ω (om, deg) |
20.023948 |
| ω (w, deg) |
255.156809 |
| M (ma, deg) |
359.999494 |
Magnitude
Scatter + Global Linear
$$
M_a = (0.773 + 5.058\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
0.773 |
| n |
5.058 |
| gf |
0.999 |
| gb |
-0.500 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 1999-03-13 |
2002-01-17 |
+0.3100 |
-0.124 |
| 2002-02-15 |
2005-08-28 |
-0.2027 |
-0.528 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
00:17:11.76 |
+37:05:42.5 |
HIP 1473 |
23.02 |
| 2026-07-29 12:00 |
00:17:09.94 |
+37:05:58.7 |
HIP 1473 |
23.45 |
| 2026-07-30 00:00 |
00:17:08.10 |
+37:06:14.7 |
HIP 1473 |
23.88 |
| 2026-07-30 12:00 |
00:17:06.24 |
+37:06:30.6 |
HIP 1473 |
24.32 |
| 2026-07-31 00:00 |
00:17:04.36 |
+37:06:46.2 |
HIP 1473 |
24.75 |
| 2026-07-31 12:00 |
00:17:02.45 |
+37:07:01.6 |
HIP 1473 |
25.19 |
| 2026-08-01 00:00 |
00:17:00.52 |
+37:07:16.8 |
HIP 1473 |
25.63 |
| 2026-08-01 12:00 |
00:16:58.56 |
+37:07:31.9 |
HIP 1473 |
26.07 |
| 2026-08-02 00:00 |
00:16:56.58 |
+37:07:46.7 |
HIP 1411 |
26.00 |
| 2026-08-02 12:00 |
00:16:54.58 |
+37:08:01.3 |
HIP 1411 |
25.91 |
| 2026-08-03 00:00 |
00:16:52.56 |
+37:08:15.7 |
HIP 1411 |
25.83 |
| 2026-08-03 12:00 |
00:16:50.51 |
+37:08:29.9 |
HIP 1411 |
25.76 |
| 2026-08-04 00:00 |
00:16:48.45 |
+37:08:43.8 |
HIP 1411 |
25.71 |
| 2026-08-04 12:00 |
00:16:46.35 |
+37:08:57.6 |
HIP 1411 |
25.67 |
| 2026-08-05 00:00 |
00:16:44.24 |
+37:09:11.2 |
HIP 1411 |
25.65 |
| 2026-08-05 12:00 |
00:16:42.11 |
+37:09:24.5 |
HIP 1411 |
25.64 |
| 2026-08-06 00:00 |
00:16:39.95 |
+37:09:37.6 |
HIP 1411 |
25.64 |
| 2026-08-06 12:00 |
00:16:37.77 |
+37:09:50.5 |
HIP 1411 |
25.66 |
| 2026-08-07 00:00 |
00:16:35.57 |
+37:10:03.2 |
HIP 1411 |
25.69 |
| 2026-08-07 12:00 |
00:16:33.34 |
+37:10:15.7 |
HIP 1411 |
25.74 |
| 2026-08-08 00:00 |
00:16:31.10 |
+37:10:28.0 |
HIP 1411 |
25.80 |
| 2026-08-08 12:00 |
00:16:28.83 |
+37:10:40.0 |
HIP 1411 |
25.87 |
| 2026-08-09 00:00 |
00:16:26.55 |
+37:10:51.8 |
HIP 1411 |
25.96 |
| 2026-08-09 12:00 |
00:16:24.24 |
+37:11:03.4 |
HIP 1411 |
26.07 |
| 2026-08-10 00:00 |
00:16:21.91 |
+37:11:14.8 |
HIP 1411 |
26.19 |
| 2026-08-10 12:00 |
00:16:19.56 |
+37:11:25.9 |
HIP 1411 |
26.32 |
| 2026-08-11 00:00 |
00:16:17.19 |
+37:11:36.8 |
HIP 1411 |
26.47 |
| 2026-08-11 12:00 |
00:16:14.79 |
+37:11:47.5 |
HIP 1411 |
26.63 |
| 2026-08-12 00:00 |
00:16:12.38 |
+37:11:58.0 |
HIP 1411 |
26.81 |
| 2026-08-12 12:00 |
00:16:09.95 |
+37:12:08.2 |
HIP 1411 |
27.00 |
| 2026-08-13 00:00 |
00:16:07.50 |
+37:12:18.2 |
HIP 1411 |
27.20 |
| 2026-08-13 12:00 |
00:16:05.03 |
+37:12:28.0 |
HIP 1411 |
27.42 |
| 2026-08-14 00:00 |
00:16:02.53 |
+37:12:37.6 |
HIP 1411 |
27.65 |
| 2026-08-14 12:00 |
00:16:00.02 |
+37:12:46.9 |
HIP 1411 |
27.89 |
| 2026-08-15 00:00 |
00:15:57.49 |
+37:12:56.0 |
HIP 1411 |
28.15 |
| 2026-08-15 12:00 |
00:15:54.94 |
+37:13:04.8 |
HIP 1411 |
28.42 |
| 2026-08-16 00:00 |
00:15:52.37 |
+37:13:13.5 |
HIP 1411 |
28.70 |
| 2026-08-16 12:00 |
00:15:49.78 |
+37:13:21.8 |
HIP 1411 |
29.00 |
| 2026-08-17 00:00 |
00:15:47.18 |
+37:13:30.0 |
HIP 1411 |
29.31 |
| 2026-08-17 12:00 |
00:15:44.55 |
+37:13:37.9 |
HIP 1411 |
29.63 |
| 2026-08-18 00:00 |
00:15:41.91 |
+37:13:45.6 |
HIP 1411 |
29.96 |
| 2026-08-18 12:00 |
00:15:39.25 |
+37:13:53.1 |
HIP 1411 |
30.30 |
| 2026-08-19 00:00 |
00:15:36.57 |
+37:14:00.3 |
HIP 1411 |
30.65 |