| Parameter |
Value |
| Designation |
P/2007 S1 (Zhao) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2007-12-06T20:05:23.029440Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:12Z |
| Obs used |
78 |
| NEO |
- |
| M1 |
13.500 |
| K1 |
10.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2007-09-29.0000000 |
| e |
0.34338434 |
| q (au) |
2.494391 |
| a (au) |
3.798860 |
| i (deg) |
5.973039 |
| Ω (om, deg) |
141.618584 |
| ω (w, deg) |
245.425020 |
| M (ma, deg) |
350.836814 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.850 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.850 |
| n |
6.000 |
| gf |
0.876 |
| gb |
-0.879 |
| k |
1.000 |
| δ90 |
3.511 |
| 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) |
| 2026-06-01 00:00 |
13:04:49.76 |
-00:18:29.9 |
HIP 63803 |
25.35 |
| 2026-06-01 12:00 |
13:04:43.94 |
-00:18:20.5 |
HIP 63803 |
25.39 |
| 2026-06-02 00:00 |
13:04:38.31 |
-00:18:12.3 |
HIP 63803 |
25.49 |
| 2026-06-02 12:00 |
13:04:32.85 |
-00:18:05.3 |
HIP 63803 |
25.65 |
| 2026-06-03 00:00 |
13:04:27.57 |
-00:17:59.6 |
HIP 63803 |
25.85 |
| 2026-06-03 12:00 |
13:04:22.47 |
-00:17:55.1 |
HIP 63803 |
26.09 |
| 2026-06-04 00:00 |
13:04:17.54 |
-00:17:51.9 |
HIP 63803 |
26.36 |
| 2026-06-04 12:00 |
13:04:12.80 |
-00:17:49.9 |
HIP 63803 |
26.65 |
| 2026-06-05 00:00 |
13:04:08.24 |
-00:17:49.1 |
HIP 63803 |
26.96 |
| 2026-06-05 12:00 |
13:04:03.86 |
-00:17:49.6 |
HIP 63803 |
27.28 |
| 2026-06-06 00:00 |
13:03:59.65 |
-00:17:51.3 |
HIP 63803 |
27.61 |
| 2026-06-06 12:00 |
13:03:55.63 |
-00:17:54.2 |
HIP 63803 |
27.93 |
| 2026-06-07 00:00 |
13:03:51.79 |
-00:17:58.3 |
HIP 63803 |
28.25 |
| 2026-06-07 12:00 |
13:03:48.13 |
-00:18:03.7 |
HIP 63803 |
28.56 |
| 2026-06-08 00:00 |
13:03:44.65 |
-00:18:10.3 |
HIP 63803 |
28.86 |
| 2026-06-08 12:00 |
13:03:41.35 |
-00:18:18.1 |
HIP 63803 |
29.14 |
| 2026-06-09 00:00 |
13:03:38.23 |
-00:18:27.1 |
HIP 63803 |
29.40 |
| 2026-06-09 12:00 |
13:03:35.29 |
-00:18:37.4 |
HIP 63803 |
29.64 |
| 2026-06-10 00:00 |
13:03:32.54 |
-00:18:48.8 |
HIP 63803 |
29.85 |
| 2026-06-10 12:00 |
13:03:29.96 |
-00:19:01.4 |
HIP 63803 |
30.04 |
| 2026-06-11 00:00 |
13:03:27.57 |
-00:19:15.3 |
HIP 63659 |
30.03 |
| 2026-06-11 12:00 |
13:03:25.36 |
-00:19:30.4 |
HIP 63659 |
29.61 |
| 2026-06-12 00:00 |
13:03:23.33 |
-00:19:46.6 |
HIP 63659 |
29.20 |
| 2026-06-12 12:00 |
13:03:21.49 |
-00:20:04.1 |
HIP 63659 |
28.79 |
| 2026-06-13 00:00 |
13:03:19.82 |
-00:20:22.7 |
HIP 63659 |
28.37 |
| 2026-06-13 12:00 |
13:03:18.34 |
-00:20:42.5 |
HIP 63659 |
27.96 |
| 2026-06-14 00:00 |
13:03:17.04 |
-00:21:03.6 |
HIP 63659 |
27.53 |
| 2026-06-14 12:00 |
13:03:15.92 |
-00:21:25.8 |
HIP 63659 |
27.10 |
| 2026-06-15 00:00 |
13:03:14.98 |
-00:21:49.1 |
HIP 63659 |
26.67 |
| 2026-06-15 12:00 |
13:03:14.22 |
-00:22:13.7 |
HIP 63659 |
26.22 |
| 2026-06-16 00:00 |
13:03:13.65 |
-00:22:39.4 |
HIP 63659 |
25.77 |
| 2026-06-16 12:00 |
13:03:13.26 |
-00:23:06.3 |
HIP 63659 |
25.32 |
| 2026-06-17 00:00 |
13:03:13.05 |
-00:23:34.3 |
HIP 63659 |
24.85 |
| 2026-06-17 12:00 |
13:03:13.02 |
-00:24:03.5 |
HIP 63659 |
24.38 |
| 2026-06-18 00:00 |
13:03:13.17 |
-00:24:33.9 |
HIP 63659 |
23.90 |
| 2026-06-18 12:00 |
13:03:13.50 |
-00:25:05.4 |
HIP 63659 |
23.41 |
| 2026-06-19 00:00 |
13:03:14.01 |
-00:25:38.0 |
HIP 63659 |
22.92 |
| 2026-06-19 12:00 |
13:03:14.69 |
-00:26:11.7 |
HIP 63659 |
22.43 |
| 2026-06-20 00:00 |
13:03:15.56 |
-00:26:46.6 |
HIP 63659 |
21.94 |
| 2026-06-20 12:00 |
13:03:16.61 |
-00:27:22.6 |
HIP 63659 |
21.45 |
| 2026-06-21 00:00 |
13:03:17.83 |
-00:27:59.7 |
HIP 63659 |
20.98 |
| 2026-06-21 12:00 |
13:03:19.24 |
-00:28:37.9 |
HIP 63659 |
20.51 |
| 2026-06-22 00:00 |
13:03:20.81 |
-00:29:17.2 |
HIP 63659 |
20.06 |