| 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 |
1.000 |
| gb |
-0.502 |
| 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 |
03:21:46.74 |
+31:54:06.1 |
HIP 15710 |
19.14 |
| 2026-05-12 12:00 |
03:21:52.28 |
+31:54:21.7 |
HIP 15710 |
18.95 |
| 2026-05-13 00:00 |
03:21:57.82 |
+31:54:37.4 |
HIP 15710 |
18.83 |
| 2026-05-13 12:00 |
03:22:03.37 |
+31:54:53.2 |
HIP 15710 |
18.79 |
| 2026-05-14 00:00 |
03:22:08.91 |
+31:55:09.1 |
HIP 15710 |
18.83 |
| 2026-05-14 12:00 |
03:22:14.46 |
+31:55:25.2 |
HIP 15710 |
18.95 |
| 2026-05-15 00:00 |
03:22:20.00 |
+31:55:41.4 |
HIP 15721 |
18.85 |
| 2026-05-15 12:00 |
03:22:25.55 |
+31:55:57.7 |
HIP 15721 |
18.47 |
| 2026-05-16 00:00 |
03:22:31.09 |
+31:56:14.1 |
HIP 15721 |
18.16 |
| 2026-05-16 12:00 |
03:22:36.63 |
+31:56:30.6 |
HIP 15721 |
17.92 |
| 2026-05-17 00:00 |
03:22:42.16 |
+31:56:47.2 |
HIP 15721 |
17.76 |
| 2026-05-17 12:00 |
03:22:47.70 |
+31:57:03.9 |
HIP 15721 |
17.68 |
| 2026-05-18 00:00 |
03:22:53.23 |
+31:57:20.8 |
HIP 15721 |
17.68 |
| 2026-05-18 12:00 |
03:22:58.76 |
+31:57:37.7 |
HIP 15721 |
17.76 |
| 2026-05-19 00:00 |
03:23:04.29 |
+31:57:54.8 |
HIP 15721 |
17.92 |
| 2026-05-19 12:00 |
03:23:09.81 |
+31:58:11.9 |
HIP 15721 |
18.15 |
| 2026-05-20 00:00 |
03:23:15.32 |
+31:58:29.2 |
HIP 15721 |
18.46 |
| 2026-05-20 12:00 |
03:23:20.84 |
+31:58:46.6 |
HIP 15721 |
18.84 |
| 2026-05-21 00:00 |
03:23:26.34 |
+31:59:04.1 |
HIP 15721 |
19.28 |
| 2026-05-21 12:00 |
03:23:31.85 |
+31:59:21.6 |
HIP 15721 |
19.78 |
| 2026-05-22 00:00 |
03:23:37.34 |
+31:59:39.3 |
HIP 15721 |
20.35 |
| 2026-05-22 12:00 |
03:23:42.84 |
+31:59:57.1 |
HIP 15721 |
20.96 |
| 2026-05-23 00:00 |
03:23:48.32 |
+32:00:14.9 |
HIP 15721 |
21.62 |
| 2026-05-23 12:00 |
03:23:53.80 |
+32:00:32.9 |
HIP 15721 |
22.32 |
| 2026-05-24 00:00 |
03:23:59.27 |
+32:00:51.0 |
HIP 15721 |
23.06 |
| 2026-05-24 12:00 |
03:24:04.73 |
+32:01:09.1 |
HIP 15721 |
23.84 |
| 2026-05-25 00:00 |
03:24:10.19 |
+32:01:27.4 |
HIP 15953 |
23.54 |
| 2026-05-25 12:00 |
03:24:15.64 |
+32:01:45.7 |
HIP 15953 |
23.03 |
| 2026-05-26 00:00 |
03:24:21.08 |
+32:02:04.1 |
HIP 15953 |
22.57 |
| 2026-05-26 12:00 |
03:24:26.51 |
+32:02:22.6 |
HIP 15953 |
22.16 |
| 2026-05-27 00:00 |
03:24:31.94 |
+32:02:41.2 |
HIP 15953 |
21.82 |
| 2026-05-27 12:00 |
03:24:37.35 |
+32:03:00.0 |
HIP 15937 |
21.18 |
| 2026-05-28 00:00 |
03:24:42.76 |
+32:03:18.7 |
HIP 15937 |
20.50 |
| 2026-05-28 12:00 |
03:24:48.15 |
+32:03:37.5 |
HIP 15937 |
19.87 |
| 2026-05-29 00:00 |
03:24:53.54 |
+32:03:56.5 |
HIP 15937 |
19.29 |
| 2026-05-29 12:00 |
03:24:58.92 |
+32:04:15.5 |
HIP 15937 |
18.76 |
| 2026-05-30 00:00 |
03:25:04.28 |
+32:04:34.6 |
HIP 15937 |
18.29 |
| 2026-05-30 12:00 |
03:25:09.64 |
+32:04:53.8 |
HIP 15937 |
17.89 |
| 2026-05-31 00:00 |
03:25:14.98 |
+32:05:13.0 |
HIP 15937 |
17.55 |
| 2026-05-31 12:00 |
03:25:20.32 |
+32:05:32.3 |
HIP 15937 |
17.29 |
| 2026-06-01 00:00 |
03:25:25.64 |
+32:05:51.7 |
HIP 15937 |
17.10 |
| 2026-06-01 12:00 |
03:25:30.95 |
+32:06:11.2 |
HIP 15937 |
16.99 |
| 2026-06-02 00:00 |
03:25:36.25 |
+32:06:30.8 |
HIP 15937 |
16.96 |