| Parameter |
Value |
| Designation |
C/2015 F2 (Polonia) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2015-04-28T19:46:02.029440Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:09Z |
| Obs used |
308 |
| NEO |
- |
| M1 |
14.900 |
| K1 |
21.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2015-05-14.0000000 |
| e |
0.96844230 |
| q (au) |
1.210552 |
| a (au) |
38.359944 |
| i (deg) |
28.693745 |
| Ω (om, deg) |
262.551624 |
| ω (w, deg) |
352.034051 |
| M (ma, deg) |
0.062959 |
Magnitude
Scatter + Global Linear
$$
M_a = (15.056 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
15.056 |
| n |
6.000 |
| gf |
0.996 |
| gb |
-0.501 |
| k |
1.000 |
| δ90 |
9.999 |
| 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) |
| 2026-09-20 00:00 |
03:32:39.50 |
+33:10:06.4 |
HIP 16557 |
13.31 |
| 2026-09-20 12:00 |
03:32:36.84 |
+33:10:11.1 |
HIP 16557 |
13.54 |
| 2026-09-21 00:00 |
03:32:34.14 |
+33:10:15.6 |
HIP 16557 |
13.80 |
| 2026-09-21 12:00 |
03:32:31.39 |
+33:10:19.9 |
HIP 16557 |
14.08 |
| 2026-09-22 00:00 |
03:32:28.61 |
+33:10:24.0 |
HIP 16557 |
14.38 |
| 2026-09-22 12:00 |
03:32:25.78 |
+33:10:27.9 |
HIP 16557 |
14.72 |
| 2026-09-23 00:00 |
03:32:22.91 |
+33:10:31.5 |
HIP 16557 |
15.07 |
| 2026-09-23 12:00 |
03:32:20.00 |
+33:10:35.0 |
HIP 16557 |
15.45 |
| 2026-09-24 00:00 |
03:32:17.06 |
+33:10:38.3 |
HIP 16557 |
15.86 |
| 2026-09-24 12:00 |
03:32:14.07 |
+33:10:41.3 |
HIP 16557 |
16.28 |
| 2026-09-25 00:00 |
03:32:11.04 |
+33:10:44.2 |
HIP 16557 |
16.73 |
| 2026-09-25 12:00 |
03:32:07.97 |
+33:10:46.8 |
HIP 16557 |
17.20 |
| 2026-09-26 00:00 |
03:32:04.87 |
+33:10:49.3 |
HIP 16557 |
17.68 |
| 2026-09-26 12:00 |
03:32:01.72 |
+33:10:51.5 |
HIP 16557 |
18.19 |
| 2026-09-27 00:00 |
03:31:58.54 |
+33:10:53.5 |
HIP 16557 |
18.71 |
| 2026-09-27 12:00 |
03:31:55.31 |
+33:10:55.4 |
HIP 16557 |
19.25 |
| 2026-09-28 00:00 |
03:31:52.05 |
+33:10:57.0 |
HIP 16557 |
19.81 |
| 2026-09-28 12:00 |
03:31:48.75 |
+33:10:58.4 |
HIP 16557 |
20.38 |
| 2026-09-29 00:00 |
03:31:45.42 |
+33:10:59.5 |
HIP 16557 |
20.97 |
| 2026-09-29 12:00 |
03:31:42.04 |
+33:11:00.5 |
HIP 16557 |
21.58 |
| 2026-09-30 00:00 |
03:31:38.63 |
+33:11:01.3 |
HIP 16557 |
22.20 |
| 2026-09-30 12:00 |
03:31:35.18 |
+33:11:01.8 |
HIP 16557 |
22.83 |
| 2026-10-01 00:00 |
03:31:31.69 |
+33:11:02.2 |
HIP 16557 |
23.48 |
| 2026-10-01 12:00 |
03:31:28.17 |
+33:11:02.3 |
HIP 16557 |
24.14 |
| 2026-10-02 00:00 |
03:31:24.61 |
+33:11:02.2 |
HIP 16557 |
24.81 |
| 2026-10-02 12:00 |
03:31:21.01 |
+33:11:01.9 |
HIP 16557 |
25.50 |
| 2026-10-03 00:00 |
03:31:17.38 |
+33:11:01.4 |
HIP 16557 |
26.19 |
| 2026-10-03 12:00 |
03:31:13.71 |
+33:11:00.6 |
HIP 16557 |
26.90 |
| 2026-10-04 00:00 |
03:31:10.01 |
+33:10:59.7 |
HIP 16557 |
27.62 |
| 2026-10-04 12:00 |
03:31:06.27 |
+33:10:58.5 |
HIP 16557 |
28.36 |
| 2026-10-05 00:00 |
03:31:02.49 |
+33:10:57.1 |
HIP 16557 |
29.10 |
| 2026-10-05 12:00 |
03:30:58.68 |
+33:10:55.5 |
HIP 16557 |
29.85 |
| 2026-10-06 00:00 |
03:30:54.84 |
+33:10:53.7 |
HIP 16557 |
30.61 |
| 2026-10-06 12:00 |
03:30:50.96 |
+33:10:51.6 |
HIP 16557 |
31.39 |
| 2026-10-07 00:00 |
03:30:47.05 |
+33:10:49.4 |
HIP 16557 |
32.17 |
| 2026-10-07 12:00 |
03:30:43.11 |
+33:10:46.9 |
HIP 16557 |
32.96 |
| 2026-10-08 00:00 |
03:30:39.13 |
+33:10:44.2 |
HIP 16557 |
33.76 |
| 2026-10-08 12:00 |
03:30:35.12 |
+33:10:41.3 |
HIP 16557 |
34.57 |
| 2026-10-09 00:00 |
03:30:31.08 |
+33:10:38.1 |
HIP 16557 |
35.39 |
| 2026-10-09 12:00 |
03:30:27.00 |
+33:10:34.7 |
HIP 16154 |
36.05 |
| 2026-10-10 00:00 |
03:30:22.89 |
+33:10:31.2 |
HIP 16154 |
35.33 |
| 2026-10-10 12:00 |
03:30:18.75 |
+33:10:27.3 |
HIP 16154 |
34.61 |
| 2026-10-11 00:00 |
03:30:14.58 |
+33:10:23.3 |
HIP 16154 |
33.90 |