| Parameter |
Value |
| Designation |
P/2017 P1 (PANSTARRS) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2018-06-18T14:00:59.025600Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:35Z |
| Obs used |
46 |
| NEO |
- |
| M1 |
14.200 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2017-08-29.0000000 |
| e |
0.30846643 |
| q (au) |
5.438117 |
| a (au) |
7.863851 |
| i (deg) |
7.701554 |
| Ω (om, deg) |
221.393844 |
| ω (w, deg) |
122.270978 |
| M (ma, deg) |
346.878497 |
Magnitude
Scatter + Global Linear
$$
M_a = (16.305 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
16.305 |
| n |
2.000 |
| gf |
0.977 |
| gb |
-0.687 |
| k |
0.800 |
| δ90 |
9.531 |
| 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 |
09:02:27.25 |
+09:36:47.1 |
HIP 44475 |
24.86 |
| 2026-07-29 12:00 |
09:02:40.52 |
+09:35:51.9 |
HIP 44475 |
23.25 |
| 2026-07-30 00:00 |
09:02:53.79 |
+09:34:56.6 |
HIP 44475 |
22.05 |
| 2026-07-30 12:00 |
09:03:07.07 |
+09:34:01.0 |
HIP 44475 |
21.33 |
| 2026-07-31 00:00 |
09:03:20.35 |
+09:33:05.1 |
HIP 44475 |
21.15 |
| 2026-07-31 12:00 |
09:03:33.64 |
+09:32:09.1 |
HIP 44475 |
21.51 |
| 2026-08-01 00:00 |
09:03:46.93 |
+09:31:12.8 |
HIP 44475 |
22.39 |
| 2026-08-01 12:00 |
09:04:00.23 |
+09:30:16.3 |
HIP 44475 |
23.74 |
| 2026-08-02 00:00 |
09:04:13.52 |
+09:29:19.6 |
HIP 44475 |
25.48 |
| 2026-08-02 12:00 |
09:04:26.82 |
+09:28:22.7 |
HIP 44475 |
27.54 |
| 2026-08-03 00:00 |
09:04:40.12 |
+09:27:25.5 |
HIP 44475 |
29.85 |
| 2026-08-03 12:00 |
09:04:53.43 |
+09:26:28.1 |
HIP 44475 |
32.36 |
| 2026-08-04 00:00 |
09:05:06.73 |
+09:25:30.6 |
HIP 44748 |
33.93 |
| 2026-08-04 12:00 |
09:05:20.03 |
+09:24:32.8 |
HIP 44748 |
31.48 |
| 2026-08-05 00:00 |
09:05:33.34 |
+09:23:34.8 |
HIP 44748 |
29.23 |
| 2026-08-05 12:00 |
09:05:46.64 |
+09:22:36.6 |
HIP 44748 |
27.22 |
| 2026-08-06 00:00 |
09:05:59.94 |
+09:21:38.2 |
HIP 44748 |
25.52 |
| 2026-08-06 12:00 |
09:06:13.25 |
+09:20:39.5 |
HIP 44748 |
24.19 |
| 2026-08-07 00:00 |
09:06:26.54 |
+09:19:40.7 |
HIP 44748 |
23.29 |
| 2026-08-07 12:00 |
09:06:39.84 |
+09:18:41.7 |
HIP 44748 |
22.88 |
| 2026-08-08 00:00 |
09:06:53.14 |
+09:17:42.5 |
HIP 44748 |
22.98 |
| 2026-08-08 12:00 |
09:07:06.43 |
+09:16:43.1 |
HIP 44748 |
23.59 |
| 2026-08-09 00:00 |
09:07:19.71 |
+09:15:43.5 |
HIP 44748 |
24.66 |
| 2026-08-09 12:00 |
09:07:32.99 |
+09:14:43.7 |
HIP 44748 |
26.15 |
| 2026-08-10 00:00 |
09:07:46.27 |
+09:13:43.7 |
HIP 44748 |
27.97 |
| 2026-08-10 12:00 |
09:07:59.54 |
+09:12:43.6 |
HIP 44748 |
30.08 |
| 2026-08-11 00:00 |
09:08:12.81 |
+09:11:43.2 |
HIP 44748 |
32.42 |
| 2026-08-11 12:00 |
09:08:26.07 |
+09:10:42.7 |
HIP 44748 |
34.94 |
| 2026-08-12 00:00 |
09:08:39.32 |
+09:09:42.0 |
HIP 44748 |
37.60 |
| 2026-08-12 12:00 |
09:08:52.56 |
+09:08:41.1 |
HIP 44978 |
39.27 |
| 2026-08-13 00:00 |
09:09:05.79 |
+09:07:40.1 |
HIP 45111 |
36.00 |
| 2026-08-13 12:00 |
09:09:19.02 |
+09:06:38.9 |
HIP 45111 |
32.59 |
| 2026-08-14 00:00 |
09:09:32.23 |
+09:05:37.5 |
HIP 45111 |
29.17 |
| 2026-08-14 12:00 |
09:09:45.44 |
+09:04:36.0 |
HIP 45111 |
25.76 |
| 2026-08-15 00:00 |
09:09:58.63 |
+09:03:34.3 |
HIP 45111 |
22.36 |
| 2026-08-15 12:00 |
09:10:11.82 |
+09:02:32.4 |
HIP 45111 |
18.95 |
| 2026-08-16 00:00 |
09:10:24.99 |
+09:01:30.4 |
HIP 45111 |
15.56 |
| 2026-08-16 12:00 |
09:10:38.15 |
+09:00:28.2 |
HIP 45111 |
12.18 |
| 2026-08-17 00:00 |
09:10:51.29 |
+08:59:25.9 |
HIP 45111 |
8.83 |
| 2026-08-17 12:00 |
09:11:04.43 |
+08:58:23.5 |
HIP 45111 |
5.55 |
| 2026-08-18 00:00 |
09:11:17.54 |
+08:57:20.9 |
HIP 45111 |
2.60 |
| 2026-08-18 12:00 |
09:11:30.65 |
+08:56:18.2 |
HIP 45111 |
2.44 |
| 2026-08-19 00:00 |
09:11:43.74 |
+08:55:15.3 |
HIP 45111 |
5.32 |