| Parameter |
Value |
| Designation |
P/2017 D4 (PANSTARRS) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2016-09-06T15:17:49.675200Z |
| Orbit solution date (soln_date, UTC) |
2022-07-31T01:43:23Z |
| Obs used |
91 |
| NEO |
- |
| M1 |
16.300 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2017-03-06.0000000 |
| e |
0.62891585 |
| q (au) |
2.754615 |
| a (au) |
7.423156 |
| i (deg) |
10.339594 |
| Ω (om, deg) |
266.104140 |
| ω (w, deg) |
209.796281 |
| M (ma, deg) |
8.789572 |
Magnitude
Scatter + Global Linear
$$
M_a = (15.387 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
15.387 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-1.000 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
19:53:55.58 |
-15:32:55.9 |
HIP 97972 |
24.46 |
| 2026-05-12 12:00 |
19:53:53.17 |
-15:32:45.9 |
HIP 97972 |
24.87 |
| 2026-05-13 00:00 |
19:53:50.67 |
-15:32:36.2 |
HIP 97972 |
25.29 |
| 2026-05-13 12:00 |
19:53:48.09 |
-15:32:26.7 |
HIP 97972 |
25.74 |
| 2026-05-14 00:00 |
19:53:45.42 |
-15:32:17.4 |
HIP 97972 |
26.19 |
| 2026-05-14 12:00 |
19:53:42.68 |
-15:32:08.4 |
HIP 97972 |
26.66 |
| 2026-05-15 00:00 |
19:53:39.86 |
-15:31:59.7 |
HIP 97972 |
27.15 |
| 2026-05-15 12:00 |
19:53:36.95 |
-15:31:51.2 |
HIP 97972 |
27.65 |
| 2026-05-16 00:00 |
19:53:33.97 |
-15:31:43.0 |
HIP 97972 |
28.17 |
| 2026-05-16 12:00 |
19:53:30.90 |
-15:31:35.0 |
HIP 97972 |
28.70 |
| 2026-05-17 00:00 |
19:53:27.76 |
-15:31:27.3 |
HIP 97972 |
29.26 |
| 2026-05-17 12:00 |
19:53:24.54 |
-15:31:19.8 |
HIP 97972 |
29.83 |
| 2026-05-18 00:00 |
19:53:21.24 |
-15:31:12.6 |
HIP 97972 |
30.42 |
| 2026-05-18 12:00 |
19:53:17.85 |
-15:31:05.7 |
HIP 97972 |
31.03 |
| 2026-05-19 00:00 |
19:53:14.39 |
-15:30:59.0 |
HIP 97972 |
31.65 |
| 2026-05-19 12:00 |
19:53:10.86 |
-15:30:52.6 |
HIP 97972 |
32.30 |
| 2026-05-20 00:00 |
19:53:07.24 |
-15:30:46.4 |
HIP 97715 |
31.75 |
| 2026-05-20 12:00 |
19:53:03.55 |
-15:30:40.5 |
HIP 97715 |
31.17 |
| 2026-05-21 00:00 |
19:52:59.78 |
-15:30:34.8 |
HIP 97715 |
30.58 |
| 2026-05-21 12:00 |
19:52:55.93 |
-15:30:29.4 |
HIP 97715 |
30.00 |
| 2026-05-22 00:00 |
19:52:52.00 |
-15:30:24.3 |
HIP 97715 |
29.41 |
| 2026-05-22 12:00 |
19:52:48.01 |
-15:30:19.4 |
HIP 97715 |
28.83 |
| 2026-05-23 00:00 |
19:52:43.93 |
-15:30:14.7 |
HIP 97715 |
28.26 |
| 2026-05-23 12:00 |
19:52:39.78 |
-15:30:10.3 |
HIP 97715 |
27.70 |
| 2026-05-24 00:00 |
19:52:35.55 |
-15:30:06.2 |
HIP 97715 |
27.14 |
| 2026-05-24 12:00 |
19:52:31.26 |
-15:30:02.3 |
HIP 97715 |
26.61 |
| 2026-05-25 00:00 |
19:52:26.88 |
-15:29:58.7 |
HIP 97715 |
26.08 |
| 2026-05-25 12:00 |
19:52:22.43 |
-15:29:55.3 |
HIP 97715 |
25.58 |
| 2026-05-26 00:00 |
19:52:17.91 |
-15:29:52.2 |
HIP 97715 |
25.10 |
| 2026-05-26 12:00 |
19:52:13.32 |
-15:29:49.3 |
HIP 97715 |
24.65 |
| 2026-05-27 00:00 |
19:52:08.66 |
-15:29:46.7 |
HIP 97715 |
24.24 |
| 2026-05-27 12:00 |
19:52:03.92 |
-15:29:44.3 |
HIP 97620 |
23.69 |
| 2026-05-28 00:00 |
19:51:59.11 |
-15:29:42.2 |
HIP 97620 |
22.54 |
| 2026-05-28 12:00 |
19:51:54.23 |
-15:29:40.3 |
HIP 97620 |
21.38 |
| 2026-05-29 00:00 |
19:51:49.28 |
-15:29:38.7 |
HIP 97620 |
20.21 |
| 2026-05-29 12:00 |
19:51:44.26 |
-15:29:37.3 |
HIP 97620 |
19.02 |
| 2026-05-30 00:00 |
19:51:39.17 |
-15:29:36.2 |
HIP 97620 |
17.83 |
| 2026-05-30 12:00 |
19:51:34.01 |
-15:29:35.3 |
HIP 97620 |
16.62 |
| 2026-05-31 00:00 |
19:51:28.78 |
-15:29:34.7 |
HIP 97620 |
15.40 |
| 2026-05-31 12:00 |
19:51:23.48 |
-15:29:34.3 |
HIP 97620 |
14.17 |
| 2026-06-01 00:00 |
19:51:18.11 |
-15:29:34.2 |
HIP 97620 |
12.94 |
| 2026-06-01 12:00 |
19:51:12.68 |
-15:29:34.3 |
HIP 97620 |
11.71 |
| 2026-06-02 00:00 |
19:51:07.18 |
-15:29:34.6 |
HIP 97620 |
10.49 |