| Parameter |
Value |
| Designation |
C/2015 K2 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2015-06-08T19:07:06.248640Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:11Z |
| Obs used |
54 |
| NEO |
- |
| M1 |
20.700 |
| K1 |
10.000 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2015-05-26.0000000 |
| e |
0.99444359 |
| q (au) |
1.455282 |
| a (au) |
261.910605 |
| i (deg) |
29.110346 |
| Ω (om, deg) |
223.713883 |
| ω (w, deg) |
15.770089 |
| M (ma, deg) |
359.996792 |
Magnitude
Scatter + Global Linear
$$
M_a = (20.000 + 3.100\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
20.000 |
| n |
3.100 |
| gf |
1.000 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
01:55:52.32 |
+17:22:28.5 |
HIP 8968 |
12.21 |
| 2026-03-26 12:00 |
01:55:56.54 |
+17:22:45.8 |
HIP 8968 |
12.91 |
| 2026-03-27 00:00 |
01:56:00.77 |
+17:23:03.2 |
HIP 9072 |
13.48 |
| 2026-03-27 12:00 |
01:56:05.02 |
+17:23:20.6 |
HIP 9072 |
12.49 |
| 2026-03-28 00:00 |
01:56:09.28 |
+17:23:38.3 |
HIP 9072 |
11.50 |
| 2026-03-28 12:00 |
01:56:13.55 |
+17:23:56.0 |
HIP 9072 |
10.52 |
| 2026-03-29 00:00 |
01:56:17.84 |
+17:24:13.8 |
HIP 9072 |
9.56 |
| 2026-03-29 12:00 |
01:56:22.14 |
+17:24:31.8 |
HIP 9072 |
8.62 |
| 2026-03-30 00:00 |
01:56:26.45 |
+17:24:49.9 |
HIP 9072 |
7.70 |
| 2026-03-30 12:00 |
01:56:30.78 |
+17:25:08.0 |
HIP 9072 |
6.83 |
| 2026-03-31 00:00 |
01:56:35.12 |
+17:25:26.3 |
HIP 9072 |
6.02 |
| 2026-03-31 12:00 |
01:56:39.46 |
+17:25:44.7 |
HIP 9072 |
5.31 |
| 2026-04-01 00:00 |
01:56:43.82 |
+17:26:03.2 |
HIP 9072 |
4.73 |
| 2026-04-01 12:00 |
01:56:48.20 |
+17:26:21.8 |
HIP 9072 |
4.35 |
| 2026-04-02 00:00 |
01:56:52.58 |
+17:26:40.6 |
HIP 9072 |
4.23 |
| 2026-04-02 12:00 |
01:56:56.97 |
+17:26:59.4 |
HIP 9072 |
4.38 |
| 2026-04-03 00:00 |
01:57:01.38 |
+17:27:18.3 |
HIP 9072 |
4.78 |
| 2026-04-03 12:00 |
01:57:05.79 |
+17:27:37.3 |
HIP 9072 |
5.38 |
| 2026-04-04 00:00 |
01:57:10.22 |
+17:27:56.4 |
HIP 9072 |
6.13 |
| 2026-04-04 12:00 |
01:57:14.65 |
+17:28:15.7 |
HIP 9072 |
6.97 |
| 2026-04-05 00:00 |
01:57:19.10 |
+17:28:35.0 |
HIP 9072 |
7.87 |
| 2026-04-05 12:00 |
01:57:23.55 |
+17:28:54.4 |
HIP 9072 |
8.83 |
| 2026-04-06 00:00 |
01:57:28.01 |
+17:29:13.9 |
HIP 9072 |
9.82 |
| 2026-04-06 12:00 |
01:57:32.48 |
+17:29:33.5 |
HIP 9072 |
10.83 |
| 2026-04-07 00:00 |
01:57:36.96 |
+17:29:53.2 |
HIP 9072 |
11.87 |
| 2026-04-07 12:00 |
01:57:41.45 |
+17:30:12.9 |
HIP 9072 |
12.92 |
| 2026-04-08 00:00 |
01:57:45.95 |
+17:30:32.8 |
HIP 9072 |
13.98 |
| 2026-04-08 12:00 |
01:57:50.45 |
+17:30:52.7 |
HIP 9072 |
15.05 |
| 2026-04-09 00:00 |
01:57:54.96 |
+17:31:12.8 |
HIP 9072 |
16.14 |
| 2026-04-09 12:00 |
01:57:59.48 |
+17:31:32.9 |
HIP 9072 |
17.23 |
| 2026-04-10 00:00 |
01:58:04.00 |
+17:31:53.1 |
HIP 9072 |
18.32 |
| 2026-04-10 12:00 |
01:58:08.53 |
+17:32:13.4 |
HIP 9072 |
19.42 |
| 2026-04-11 00:00 |
01:58:13.07 |
+17:32:33.7 |
HIP 9072 |
20.53 |
| 2026-04-11 12:00 |
01:58:17.62 |
+17:32:54.2 |
HIP 9110 |
21.04 |
| 2026-04-12 00:00 |
01:58:22.17 |
+17:33:14.7 |
HIP 9110 |
21.49 |
| 2026-04-12 12:00 |
01:58:26.72 |
+17:33:35.3 |
HIP 9110 |
22.00 |
| 2026-04-13 00:00 |
01:58:31.28 |
+17:33:56.0 |
HIP 9110 |
22.55 |
| 2026-04-13 12:00 |
01:58:35.85 |
+17:34:16.7 |
HIP 9110 |
23.15 |
| 2026-04-14 00:00 |
01:58:40.42 |
+17:34:37.5 |
HIP 9110 |
23.78 |
| 2026-04-14 12:00 |
01:58:44.99 |
+17:34:58.4 |
HIP 9110 |
24.46 |
| 2026-04-15 00:00 |
01:58:49.57 |
+17:35:19.3 |
HIP 9110 |
25.16 |
| 2026-04-15 12:00 |
01:58:54.15 |
+17:35:40.3 |
HIP 9110 |
25.90 |
| 2026-04-16 00:00 |
01:58:58.74 |
+17:36:01.4 |
HIP 9110 |
26.67 |