| 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) |
| 2026-03-26 00:00 |
19:51:36.85 |
-16:05:13.1 |
HIP 97715 |
13.22 |
| 2026-03-26 12:00 |
19:51:41.99 |
-16:04:44.0 |
HIP 97715 |
12.97 |
| 2026-03-27 00:00 |
19:51:47.05 |
-16:04:15.1 |
HIP 97715 |
12.85 |
| 2026-03-27 12:00 |
19:51:52.04 |
-16:03:46.2 |
HIP 97715 |
12.85 |
| 2026-03-28 00:00 |
19:51:56.96 |
-16:03:17.5 |
HIP 97715 |
12.98 |
| 2026-03-28 12:00 |
19:52:01.80 |
-16:02:49.0 |
HIP 97715 |
13.22 |
| 2026-03-29 00:00 |
19:52:06.57 |
-16:02:20.6 |
HIP 97715 |
13.56 |
| 2026-03-29 12:00 |
19:52:11.27 |
-16:01:52.3 |
HIP 97715 |
14.00 |
| 2026-03-30 00:00 |
19:52:15.90 |
-16:01:24.2 |
HIP 97715 |
14.51 |
| 2026-03-30 12:00 |
19:52:20.45 |
-16:00:56.2 |
HIP 97715 |
15.09 |
| 2026-03-31 00:00 |
19:52:24.92 |
-16:00:28.4 |
HIP 97715 |
15.72 |
| 2026-03-31 12:00 |
19:52:29.32 |
-16:00:00.7 |
HIP 97715 |
16.40 |
| 2026-04-01 00:00 |
19:52:33.65 |
-15:59:33.2 |
HIP 97715 |
17.11 |
| 2026-04-01 12:00 |
19:52:37.90 |
-15:59:05.8 |
HIP 97715 |
17.86 |
| 2026-04-02 00:00 |
19:52:42.08 |
-15:58:38.6 |
HIP 97715 |
18.62 |
| 2026-04-02 12:00 |
19:52:46.18 |
-15:58:11.5 |
HIP 97715 |
19.40 |
| 2026-04-03 00:00 |
19:52:50.21 |
-15:57:44.6 |
HIP 97715 |
20.20 |
| 2026-04-03 12:00 |
19:52:54.16 |
-15:57:17.8 |
HIP 97715 |
20.99 |
| 2026-04-04 00:00 |
19:52:58.03 |
-15:56:51.2 |
HIP 97715 |
21.80 |
| 2026-04-04 12:00 |
19:53:01.83 |
-15:56:24.8 |
HIP 97715 |
22.60 |
| 2026-04-05 00:00 |
19:53:05.55 |
-15:55:58.5 |
HIP 97972 |
22.96 |
| 2026-04-05 12:00 |
19:53:09.19 |
-15:55:32.4 |
HIP 97972 |
22.07 |
| 2026-04-06 00:00 |
19:53:12.76 |
-15:55:06.5 |
HIP 97972 |
21.20 |
| 2026-04-06 12:00 |
19:53:16.25 |
-15:54:40.7 |
HIP 97972 |
20.36 |
| 2026-04-07 00:00 |
19:53:19.66 |
-15:54:15.1 |
HIP 97972 |
19.55 |
| 2026-04-07 12:00 |
19:53:22.99 |
-15:53:49.7 |
HIP 97972 |
18.77 |
| 2026-04-08 00:00 |
19:53:26.25 |
-15:53:24.4 |
HIP 97972 |
18.02 |
| 2026-04-08 12:00 |
19:53:29.42 |
-15:52:59.3 |
HIP 97972 |
17.29 |
| 2026-04-09 00:00 |
19:53:32.52 |
-15:52:34.4 |
HIP 97972 |
16.61 |
| 2026-04-09 12:00 |
19:53:35.54 |
-15:52:09.7 |
HIP 97972 |
15.95 |
| 2026-04-10 00:00 |
19:53:38.48 |
-15:51:45.2 |
HIP 97972 |
15.33 |
| 2026-04-10 12:00 |
19:53:41.34 |
-15:51:20.8 |
HIP 97972 |
14.75 |
| 2026-04-11 00:00 |
19:53:44.12 |
-15:50:56.7 |
HIP 97972 |
14.20 |
| 2026-04-11 12:00 |
19:53:46.82 |
-15:50:32.7 |
HIP 97972 |
13.70 |
| 2026-04-12 00:00 |
19:53:49.43 |
-15:50:08.9 |
HIP 97972 |
13.24 |
| 2026-04-12 12:00 |
19:53:51.97 |
-15:49:45.2 |
HIP 97972 |
12.82 |
| 2026-04-13 00:00 |
19:53:54.43 |
-15:49:21.8 |
HIP 97972 |
12.44 |
| 2026-04-13 12:00 |
19:53:56.81 |
-15:48:58.6 |
HIP 97972 |
12.12 |
| 2026-04-14 00:00 |
19:53:59.10 |
-15:48:35.6 |
HIP 97972 |
11.83 |
| 2026-04-14 12:00 |
19:54:01.32 |
-15:48:12.7 |
HIP 97972 |
11.60 |
| 2026-04-15 00:00 |
19:54:03.45 |
-15:47:50.1 |
HIP 97972 |
11.40 |
| 2026-04-15 12:00 |
19:54:05.50 |
-15:47:27.6 |
HIP 97972 |
11.26 |
| 2026-04-16 00:00 |
19:54:07.47 |
-15:47:05.4 |
HIP 97972 |
11.16 |