C/2015 K4 (PANSTARRS)
| Parameter |
Value |
| Designation |
C/2015 K4 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2015-05-01T18:22:16.573440Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:11Z |
| Obs used |
134 |
| NEO |
- |
| M1 |
14.400 |
| K1 |
12.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2015-06-08.0000000 |
| e |
1.00011201 |
| q (au) |
2.007657 |
| a (au) |
-17923.123229 |
| i (deg) |
80.254532 |
| Ω (om, deg) |
250.771183 |
| ω (w, deg) |
357.538399 |
| M (ma, deg) |
0.000015 |
Magnitude
Scatter + Global Linear
$$
M_a = (15.430 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
15.430 |
| n |
2.000 |
| gf |
0.981 |
| gb |
-0.546 |
| k |
1.000 |
| δ90 |
9.996 |
| 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) |
| 2026-02-03 00:00 |
03:11:50.90 |
+54:10:19.3 |
HIP 14701 |
16.96 |
| 2026-02-03 12:00 |
03:11:50.38 |
+54:09:31.1 |
HIP 14701 |
16.94 |
| 2026-02-04 00:00 |
03:11:49.94 |
+54:08:43.1 |
HIP 14701 |
16.96 |
| 2026-02-04 12:00 |
03:11:49.56 |
+54:07:55.2 |
HIP 14701 |
17.03 |
| 2026-02-05 00:00 |
03:11:49.25 |
+54:07:07.5 |
HIP 14701 |
17.15 |
| 2026-02-05 12:00 |
03:11:49.00 |
+54:06:19.8 |
HIP 14701 |
17.31 |
| 2026-02-06 00:00 |
03:11:48.83 |
+54:05:32.3 |
HIP 14701 |
17.51 |
| 2026-02-06 12:00 |
03:11:48.72 |
+54:04:45.0 |
HIP 14701 |
17.76 |
| 2026-02-07 00:00 |
03:11:48.68 |
+54:03:57.8 |
HIP 14701 |
18.05 |
| 2026-02-07 12:00 |
03:11:48.71 |
+54:03:10.7 |
HIP 14701 |
18.37 |
| 2026-02-08 00:00 |
03:11:48.80 |
+54:02:23.8 |
HIP 14701 |
18.73 |
| 2026-02-08 12:00 |
03:11:48.97 |
+54:01:37.1 |
HIP 14701 |
19.12 |
| 2026-02-09 00:00 |
03:11:49.20 |
+54:00:50.5 |
HIP 14701 |
19.54 |
| 2026-02-09 12:00 |
03:11:49.49 |
+54:00:04.1 |
HIP 14701 |
19.99 |
| 2026-02-10 00:00 |
03:11:49.86 |
+53:59:17.8 |
HIP 14701 |
20.46 |
| 2026-02-10 12:00 |
03:11:50.29 |
+53:58:31.7 |
HIP 14701 |
20.96 |
| 2026-02-11 00:00 |
03:11:50.78 |
+53:57:45.8 |
HIP 14701 |
21.49 |
| 2026-02-11 12:00 |
03:11:51.35 |
+53:57:00.1 |
HIP 14701 |
22.03 |
| 2026-02-12 00:00 |
03:11:51.98 |
+53:56:14.5 |
HIP 14701 |
22.59 |
| 2026-02-12 12:00 |
03:11:52.67 |
+53:55:29.1 |
HIP 14701 |
23.16 |
| 2026-02-13 00:00 |
03:11:53.44 |
+53:54:43.9 |
HIP 14701 |
23.76 |
| 2026-02-13 12:00 |
03:11:54.27 |
+53:53:58.9 |
HIP 14701 |
24.36 |
| 2026-02-14 00:00 |
03:11:55.16 |
+53:53:14.1 |
HIP 14701 |
24.98 |
| 2026-02-14 12:00 |
03:11:56.12 |
+53:52:29.4 |
HIP 14701 |
25.62 |
| 2026-02-15 00:00 |
03:11:57.15 |
+53:51:45.0 |
HIP 14701 |
26.26 |
| 2026-02-15 12:00 |
03:11:58.24 |
+53:51:00.7 |
HIP 14701 |
26.91 |
| 2026-02-16 00:00 |
03:11:59.39 |
+53:50:16.7 |
HIP 14701 |
27.57 |
| 2026-02-16 12:00 |
03:12:00.61 |
+53:49:32.9 |
HIP 14701 |
28.24 |
| 2026-02-17 00:00 |
03:12:01.90 |
+53:48:49.2 |
HIP 14701 |
28.92 |
| 2026-02-17 12:00 |
03:12:03.25 |
+53:48:05.8 |
HIP 14701 |
29.61 |
| 2026-02-18 00:00 |
03:12:04.67 |
+53:47:22.6 |
HIP 14701 |
30.30 |
| 2026-02-18 12:00 |
03:12:06.15 |
+53:46:39.6 |
HIP 14701 |
30.99 |
| 2026-02-19 00:00 |
03:12:07.69 |
+53:45:56.8 |
HIP 14890 |
31.66 |
| 2026-02-19 12:00 |
03:12:09.30 |
+53:45:14.3 |
HIP 14890 |
30.94 |
| 2026-02-20 00:00 |
03:12:10.97 |
+53:44:31.9 |
HIP 14890 |
30.24 |
| 2026-02-20 12:00 |
03:12:12.70 |
+53:43:49.8 |
HIP 14890 |
29.54 |
| 2026-02-21 00:00 |
03:12:14.50 |
+53:43:08.0 |
HIP 14890 |
28.84 |
| 2026-02-21 12:00 |
03:12:16.35 |
+53:42:26.3 |
HIP 14890 |
28.15 |
| 2026-02-22 00:00 |
03:12:18.28 |
+53:41:44.9 |
HIP 14890 |
27.47 |
| 2026-02-22 12:00 |
03:12:20.26 |
+53:41:03.7 |
HIP 14890 |
26.80 |
| 2026-02-23 00:00 |
03:12:22.30 |
+53:40:22.8 |
HIP 14890 |
26.14 |
| 2026-02-23 12:00 |
03:12:24.41 |
+53:39:42.1 |
HIP 14890 |
25.48 |
| 2026-02-24 00:00 |
03:12:26.58 |
+53:39:01.6 |
HIP 14890 |
24.84 |