| Parameter |
Value |
| Designation |
258P/PANSTARRS |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2020-06-18T01:33:18.210240Z |
| Orbit solution date (soln_date, UTC) |
2021-10-18T22:42:54Z |
| Obs used |
80 |
| NEO |
- |
| M1 |
16.300 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2016-06-01.0000000 |
| e |
0.21036720 |
| q (au) |
3.478121 |
| a (au) |
4.404733 |
| i (deg) |
6.745233 |
| Ω (om, deg) |
126.294862 |
| ω (w, deg) |
26.014329 |
| M (ma, deg) |
202.413786 |
Magnitude
Scatter + Global Linear
$$
M_a = (15.051 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
15.051 |
| n |
2.000 |
| gf |
0.999 |
| gb |
-0.500 |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
01:13:01.03 |
+01:54:56.0 |
HIP 5783 |
30.48 |
| 2026-06-01 12:00 |
01:13:21.60 |
+01:56:31.9 |
HIP 5818 |
29.09 |
| 2026-06-02 00:00 |
01:13:42.09 |
+01:58:07.2 |
HIP 5818 |
24.61 |
| 2026-06-02 12:00 |
01:14:02.51 |
+01:59:41.7 |
HIP 5818 |
20.57 |
| 2026-06-03 00:00 |
01:14:22.85 |
+02:01:15.5 |
HIP 5818 |
17.27 |
| 2026-06-03 12:00 |
01:14:43.11 |
+02:02:48.6 |
HIP 5818 |
15.18 |
| 2026-06-04 00:00 |
01:15:03.29 |
+02:04:21.0 |
HIP 5818 |
14.78 |
| 2026-06-04 12:00 |
01:15:23.39 |
+02:05:52.6 |
HIP 5818 |
16.19 |
| 2026-06-05 00:00 |
01:15:43.41 |
+02:07:23.4 |
HIP 5818 |
18.99 |
| 2026-06-05 12:00 |
01:16:03.35 |
+02:08:53.6 |
HIP 6000 |
18.42 |
| 2026-06-06 00:00 |
01:16:23.21 |
+02:10:22.9 |
HIP 6000 |
15.00 |
| 2026-06-06 12:00 |
01:16:42.99 |
+02:11:51.5 |
HIP 6000 |
12.83 |
| 2026-06-07 00:00 |
01:17:02.68 |
+02:13:19.4 |
HIP 6000 |
12.53 |
| 2026-06-07 12:00 |
01:17:22.29 |
+02:14:46.5 |
HIP 6000 |
14.21 |
| 2026-06-08 00:00 |
01:17:41.82 |
+02:16:12.8 |
HIP 6000 |
17.26 |
| 2026-06-08 12:00 |
01:18:01.26 |
+02:17:38.3 |
HIP 6096 |
15.80 |
| 2026-06-09 00:00 |
01:18:20.61 |
+02:19:03.1 |
HIP 6096 |
14.05 |
| 2026-06-09 12:00 |
01:18:39.87 |
+02:20:27.1 |
HIP 6096 |
13.99 |
| 2026-06-10 00:00 |
01:18:59.05 |
+02:21:50.2 |
HIP 6096 |
15.63 |
| 2026-06-10 12:00 |
01:19:18.14 |
+02:23:12.6 |
HIP 6263 |
16.56 |
| 2026-06-11 00:00 |
01:19:37.14 |
+02:24:34.2 |
HIP 6263 |
11.65 |
| 2026-06-11 12:00 |
01:19:56.05 |
+02:25:55.0 |
HIP 6263 |
6.82 |
| 2026-06-12 00:00 |
01:20:14.86 |
+02:27:15.0 |
HIP 6263 |
2.36 |
| 2026-06-12 12:00 |
01:20:33.59 |
+02:28:34.2 |
HIP 6263 |
3.50 |
| 2026-06-13 00:00 |
01:20:52.22 |
+02:29:52.6 |
HIP 6263 |
8.11 |
| 2026-06-13 12:00 |
01:21:10.75 |
+02:31:10.1 |
HIP 6263 |
12.86 |
| 2026-06-14 00:00 |
01:21:29.19 |
+02:32:26.8 |
HIP 6263 |
17.61 |
| 2026-06-14 12:00 |
01:21:47.54 |
+02:33:42.7 |
HIP 6459 |
19.61 |
| 2026-06-15 00:00 |
01:22:05.78 |
+02:34:57.7 |
HIP 6459 |
14.91 |
| 2026-06-15 12:00 |
01:22:23.93 |
+02:36:11.9 |
HIP 6459 |
10.25 |
| 2026-06-16 00:00 |
01:22:41.98 |
+02:37:25.3 |
HIP 6459 |
5.67 |
| 2026-06-16 12:00 |
01:22:59.93 |
+02:38:37.8 |
HIP 6459 |
1.74 |
| 2026-06-17 00:00 |
01:23:17.78 |
+02:39:49.4 |
HIP 6459 |
4.09 |
| 2026-06-17 12:00 |
01:23:35.53 |
+02:41:00.2 |
HIP 6459 |
8.52 |
| 2026-06-18 00:00 |
01:23:53.18 |
+02:42:10.1 |
HIP 6459 |
13.03 |
| 2026-06-18 12:00 |
01:24:10.72 |
+02:43:19.2 |
HIP 6459 |
17.53 |
| 2026-06-19 00:00 |
01:24:28.16 |
+02:44:27.4 |
HIP 6630 |
21.73 |
| 2026-06-19 12:00 |
01:24:45.50 |
+02:45:34.8 |
HIP 6679 |
18.76 |
| 2026-06-20 00:00 |
01:25:02.72 |
+02:46:41.2 |
HIP 6679 |
15.00 |
| 2026-06-20 12:00 |
01:25:19.85 |
+02:47:46.8 |
HIP 6679 |
11.75 |
| 2026-06-21 00:00 |
01:25:36.86 |
+02:48:51.5 |
HIP 6679 |
9.51 |
| 2026-06-21 12:00 |
01:25:53.77 |
+02:49:55.4 |
HIP 6679 |
9.02 |
| 2026-06-22 00:00 |
01:26:10.57 |
+02:50:58.3 |
HIP 6679 |
10.48 |