| Parameter |
Value |
| Designation |
P/2015 Q2 (Pimentel) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2015-09-10T08:08:29.523840Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:13Z |
| Obs used |
60 |
| NEO |
- |
| M1 |
15.300 |
| K1 |
10.000 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2015-09-11.0000000 |
| e |
0.75436589 |
| q (au) |
1.819120 |
| a (au) |
7.405813 |
| i (deg) |
146.202156 |
| Ω (om, deg) |
228.244773 |
| ω (w, deg) |
244.407920 |
| M (ma, deg) |
0.032314 |
Magnitude
Scatter + Global Linear
$$
M_a = (15.546 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
15.546 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.800 |
| 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) |
| 2026-09-25 00:00 |
11:55:20.11 |
+32:14:59.9 |
HIP 58250 |
18.49 |
| 2026-09-25 12:00 |
11:55:28.41 |
+32:14:32.7 |
HIP 58250 |
16.69 |
| 2026-09-26 00:00 |
11:55:36.72 |
+32:14:06.0 |
HIP 58250 |
14.89 |
| 2026-09-26 12:00 |
11:55:45.01 |
+32:13:39.9 |
HIP 58250 |
13.10 |
| 2026-09-27 00:00 |
11:55:53.31 |
+32:13:14.3 |
HIP 58250 |
11.31 |
| 2026-09-27 12:00 |
11:56:01.60 |
+32:12:49.4 |
HIP 58250 |
9.53 |
| 2026-09-28 00:00 |
11:56:09.88 |
+32:12:24.9 |
HIP 58250 |
7.76 |
| 2026-09-28 12:00 |
11:56:18.16 |
+32:12:01.1 |
HIP 58250 |
6.00 |
| 2026-09-29 00:00 |
11:56:26.44 |
+32:11:37.9 |
HIP 58250 |
4.29 |
| 2026-09-29 12:00 |
11:56:34.71 |
+32:11:15.2 |
HIP 58250 |
2.67 |
| 2026-09-30 00:00 |
11:56:42.97 |
+32:10:53.1 |
HIP 58250 |
1.50 |
| 2026-09-30 12:00 |
11:56:51.22 |
+32:10:31.6 |
HIP 58250 |
1.93 |
| 2026-10-01 00:00 |
11:56:59.47 |
+32:10:10.7 |
HIP 58250 |
3.39 |
| 2026-10-01 12:00 |
11:57:07.70 |
+32:09:50.4 |
HIP 58250 |
5.06 |
| 2026-10-02 00:00 |
11:57:15.93 |
+32:09:30.6 |
HIP 58250 |
6.77 |
| 2026-10-02 12:00 |
11:57:24.15 |
+32:09:11.5 |
HIP 58250 |
8.50 |
| 2026-10-03 00:00 |
11:57:32.36 |
+32:08:53.0 |
HIP 58250 |
10.24 |
| 2026-10-03 12:00 |
11:57:40.56 |
+32:08:35.1 |
HIP 58369 |
9.68 |
| 2026-10-04 00:00 |
11:57:48.75 |
+32:08:17.8 |
HIP 58369 |
9.04 |
| 2026-10-04 12:00 |
11:57:56.92 |
+32:08:01.1 |
HIP 58369 |
8.70 |
| 2026-10-05 00:00 |
11:58:05.09 |
+32:07:45.0 |
HIP 58369 |
8.71 |
| 2026-10-05 12:00 |
11:58:13.24 |
+32:07:29.5 |
HIP 58369 |
9.04 |
| 2026-10-06 00:00 |
11:58:21.38 |
+32:07:14.7 |
HIP 58369 |
9.67 |
| 2026-10-06 12:00 |
11:58:29.50 |
+32:07:00.5 |
HIP 58369 |
10.54 |
| 2026-10-07 00:00 |
11:58:37.61 |
+32:06:46.9 |
HIP 58369 |
11.60 |
| 2026-10-07 12:00 |
11:58:45.71 |
+32:06:34.0 |
HIP 58398 |
11.91 |
| 2026-10-08 00:00 |
11:58:53.79 |
+32:06:21.7 |
HIP 58398 |
12.36 |
| 2026-10-08 12:00 |
11:59:01.85 |
+32:06:10.0 |
HIP 58398 |
13.03 |
| 2026-10-09 00:00 |
11:59:09.90 |
+32:05:59.0 |
HIP 58398 |
13.89 |
| 2026-10-09 12:00 |
11:59:17.92 |
+32:05:48.6 |
HIP 58533 |
12.82 |
| 2026-10-10 00:00 |
11:59:25.93 |
+32:05:38.9 |
HIP 58533 |
11.37 |
| 2026-10-10 12:00 |
11:59:33.93 |
+32:05:29.8 |
HIP 58533 |
9.99 |
| 2026-10-11 00:00 |
11:59:41.90 |
+32:05:21.4 |
HIP 58533 |
8.73 |
| 2026-10-11 12:00 |
11:59:49.85 |
+32:05:13.6 |
HIP 58533 |
7.63 |
| 2026-10-12 00:00 |
11:59:57.78 |
+32:05:06.5 |
HIP 58533 |
6.77 |
| 2026-10-12 12:00 |
12:00:05.69 |
+32:05:00.0 |
HIP 58533 |
6.24 |
| 2026-10-13 00:00 |
12:00:13.58 |
+32:04:54.3 |
HIP 58533 |
6.13 |
| 2026-10-13 12:00 |
12:00:21.45 |
+32:04:49.1 |
HIP 58533 |
6.46 |
| 2026-10-14 00:00 |
12:00:29.29 |
+32:04:44.7 |
HIP 58533 |
7.15 |
| 2026-10-14 12:00 |
12:00:37.11 |
+32:04:40.9 |
HIP 58533 |
8.12 |
| 2026-10-15 00:00 |
12:00:44.91 |
+32:04:37.8 |
HIP 58533 |
9.28 |
| 2026-10-15 12:00 |
12:00:52.68 |
+32:04:35.4 |
HIP 58533 |
10.55 |
| 2026-10-16 00:00 |
12:01:00.43 |
+32:04:33.6 |
HIP 58533 |
11.91 |