| Parameter |
Value |
| Designation |
80P/Peters-Hartley |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2014-11-10T06:46:41.424960Z |
| Orbit solution date (soln_date, UTC) |
2024-08-26T13:12:38Z |
| Obs used |
179 |
| NEO |
- |
| M1 |
11.800 |
| K1 |
15.750 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2017-04-13.0000000 |
| e |
0.59940950 |
| q (au) |
1.611763 |
| a (au) |
4.023467 |
| i (deg) |
29.931105 |
| Ω (om, deg) |
259.844351 |
| ω (w, deg) |
339.165604 |
| M (ma, deg) |
108.045831 |
Magnitude
Scatter + Global Linear
$$
M_a = (11.621 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.621 |
| n |
6.000 |
| gf |
0.872 |
| gb |
-1.000 |
| k |
0.994 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
04:01:03.41 |
+32:49:52.1 |
HIP 18786 |
19.82 |
| 2026-07-29 12:00 |
04:01:17.06 |
+32:50:42.8 |
HIP 18862 |
17.01 |
| 2026-07-30 00:00 |
04:01:30.58 |
+32:51:33.3 |
HIP 18858 |
14.10 |
| 2026-07-30 12:00 |
04:01:43.99 |
+32:52:23.7 |
HIP 18858 |
11.18 |
| 2026-07-31 00:00 |
04:01:57.28 |
+32:53:13.9 |
HIP 18858 |
8.28 |
| 2026-07-31 12:00 |
04:02:10.45 |
+32:54:04.0 |
HIP 18858 |
5.43 |
| 2026-08-01 00:00 |
04:02:23.49 |
+32:54:53.9 |
HIP 18858 |
2.69 |
| 2026-08-01 12:00 |
04:02:36.41 |
+32:55:43.6 |
HIP 18858 |
1.16 |
| 2026-08-02 00:00 |
04:02:49.20 |
+32:56:33.1 |
HIP 18858 |
3.37 |
| 2026-08-02 12:00 |
04:03:01.87 |
+32:57:22.5 |
HIP 18858 |
6.07 |
| 2026-08-03 00:00 |
04:03:14.41 |
+32:58:11.7 |
HIP 18858 |
8.80 |
| 2026-08-03 12:00 |
04:03:26.83 |
+32:59:00.7 |
HIP 18858 |
11.51 |
| 2026-08-04 00:00 |
04:03:39.12 |
+32:59:49.6 |
HIP 18858 |
14.20 |
| 2026-08-04 12:00 |
04:03:51.27 |
+33:00:38.2 |
HIP 18858 |
16.87 |
| 2026-08-05 00:00 |
04:04:03.30 |
+33:01:26.7 |
HIP 18858 |
19.52 |
| 2026-08-05 12:00 |
04:04:15.20 |
+33:02:14.9 |
HIP 18858 |
22.14 |
| 2026-08-06 00:00 |
04:04:26.96 |
+33:03:03.0 |
HIP 19143 |
22.65 |
| 2026-08-06 12:00 |
04:04:38.59 |
+33:03:50.9 |
HIP 19143 |
20.55 |
| 2026-08-07 00:00 |
04:04:50.09 |
+33:04:38.6 |
HIP 19143 |
18.59 |
| 2026-08-07 12:00 |
04:05:01.45 |
+33:05:26.1 |
HIP 19143 |
16.81 |
| 2026-08-08 00:00 |
04:05:12.68 |
+33:06:13.4 |
HIP 19143 |
15.26 |
| 2026-08-08 12:00 |
04:05:23.77 |
+33:07:00.5 |
HIP 19143 |
14.00 |
| 2026-08-09 00:00 |
04:05:34.72 |
+33:07:47.4 |
HIP 19143 |
13.09 |
| 2026-08-09 12:00 |
04:05:45.53 |
+33:08:34.1 |
HIP 19143 |
12.61 |
| 2026-08-10 00:00 |
04:05:56.20 |
+33:09:20.5 |
HIP 19143 |
12.57 |
| 2026-08-10 12:00 |
04:06:06.73 |
+33:10:06.8 |
HIP 19143 |
12.98 |
| 2026-08-11 00:00 |
04:06:17.12 |
+33:10:52.8 |
HIP 19143 |
13.76 |
| 2026-08-11 12:00 |
04:06:27.36 |
+33:11:38.6 |
HIP 19240 |
13.55 |
| 2026-08-12 00:00 |
04:06:37.46 |
+33:12:24.2 |
HIP 19240 |
12.15 |
| 2026-08-12 12:00 |
04:06:47.41 |
+33:13:09.5 |
HIP 19240 |
11.06 |
| 2026-08-13 00:00 |
04:06:57.22 |
+33:13:54.7 |
HIP 19240 |
10.35 |
| 2026-08-13 12:00 |
04:07:06.88 |
+33:14:39.5 |
HIP 19240 |
10.08 |
| 2026-08-14 00:00 |
04:07:16.39 |
+33:15:24.2 |
HIP 19240 |
10.27 |
| 2026-08-14 12:00 |
04:07:25.76 |
+33:16:08.6 |
HIP 19240 |
10.87 |
| 2026-08-15 00:00 |
04:07:34.97 |
+33:16:52.8 |
HIP 19240 |
11.81 |
| 2026-08-15 12:00 |
04:07:44.04 |
+33:17:36.7 |
HIP 19240 |
12.99 |
| 2026-08-16 00:00 |
04:07:52.95 |
+33:18:20.3 |
HIP 19240 |
14.35 |
| 2026-08-16 12:00 |
04:08:01.71 |
+33:19:03.7 |
HIP 19201 |
15.77 |
| 2026-08-17 00:00 |
04:08:10.32 |
+33:19:46.9 |
HIP 19201 |
17.05 |
| 2026-08-17 12:00 |
04:08:18.77 |
+33:20:29.8 |
HIP 19337 |
18.11 |
| 2026-08-18 00:00 |
04:08:27.07 |
+33:21:12.4 |
HIP 19337 |
17.12 |
| 2026-08-18 12:00 |
04:08:35.21 |
+33:21:54.8 |
HIP 19337 |
16.30 |
| 2026-08-19 00:00 |
04:08:43.20 |
+33:22:36.9 |
HIP 19337 |
15.64 |