| 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
$$
M_a = (15.431 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
15.431 |
| n |
2.000 |
| 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) |
| 2026-09-20 00:00 |
03:41:06.76 |
+54:51:24.7 |
HIP 17285 |
8.88 |
| 2026-09-20 12:00 |
03:41:03.14 |
+54:51:47.0 |
HIP 17285 |
9.21 |
| 2026-09-21 00:00 |
03:40:59.45 |
+54:52:09.1 |
HIP 17285 |
9.57 |
| 2026-09-21 12:00 |
03:40:55.70 |
+54:52:30.9 |
HIP 17285 |
9.98 |
| 2026-09-22 00:00 |
03:40:51.90 |
+54:52:52.5 |
HIP 17285 |
10.42 |
| 2026-09-22 12:00 |
03:40:48.04 |
+54:53:13.7 |
HIP 17285 |
10.89 |
| 2026-09-23 00:00 |
03:40:44.12 |
+54:53:34.8 |
HIP 17285 |
11.38 |
| 2026-09-23 12:00 |
03:40:40.14 |
+54:53:55.5 |
HIP 17285 |
11.90 |
| 2026-09-24 00:00 |
03:40:36.11 |
+54:54:16.0 |
HIP 17285 |
12.45 |
| 2026-09-24 12:00 |
03:40:32.02 |
+54:54:36.2 |
HIP 17285 |
13.01 |
| 2026-09-25 00:00 |
03:40:27.88 |
+54:54:56.2 |
HIP 17285 |
13.59 |
| 2026-09-25 12:00 |
03:40:23.68 |
+54:55:15.8 |
HIP 17285 |
14.19 |
| 2026-09-26 00:00 |
03:40:19.42 |
+54:55:35.2 |
HIP 17285 |
14.81 |
| 2026-09-26 12:00 |
03:40:15.11 |
+54:55:54.3 |
HIP 17285 |
15.44 |
| 2026-09-27 00:00 |
03:40:10.74 |
+54:56:13.1 |
HIP 17285 |
16.08 |
| 2026-09-27 12:00 |
03:40:06.32 |
+54:56:31.6 |
HIP 17285 |
16.73 |
| 2026-09-28 00:00 |
03:40:01.84 |
+54:56:49.9 |
HIP 17285 |
17.40 |
| 2026-09-28 12:00 |
03:39:57.31 |
+54:57:07.8 |
HIP 17285 |
18.07 |
| 2026-09-29 00:00 |
03:39:52.72 |
+54:57:25.4 |
HIP 17285 |
18.76 |
| 2026-09-29 12:00 |
03:39:48.08 |
+54:57:42.8 |
HIP 17285 |
19.45 |
| 2026-09-30 00:00 |
03:39:43.39 |
+54:57:59.9 |
HIP 16941 |
19.10 |
| 2026-09-30 12:00 |
03:39:38.64 |
+54:58:16.6 |
HIP 16941 |
18.40 |
| 2026-10-01 00:00 |
03:39:33.84 |
+54:58:33.1 |
HIP 16941 |
17.70 |
| 2026-10-01 12:00 |
03:39:28.99 |
+54:58:49.2 |
HIP 16941 |
17.00 |
| 2026-10-02 00:00 |
03:39:24.09 |
+54:59:05.0 |
HIP 16941 |
16.31 |
| 2026-10-02 12:00 |
03:39:19.13 |
+54:59:20.5 |
HIP 16941 |
15.62 |
| 2026-10-03 00:00 |
03:39:14.13 |
+54:59:35.8 |
HIP 16941 |
14.93 |
| 2026-10-03 12:00 |
03:39:09.07 |
+54:59:50.7 |
HIP 16941 |
14.25 |
| 2026-10-04 00:00 |
03:39:03.96 |
+55:00:05.2 |
HIP 16941 |
13.58 |
| 2026-10-04 12:00 |
03:38:58.80 |
+55:00:19.5 |
HIP 16941 |
12.92 |
| 2026-10-05 00:00 |
03:38:53.59 |
+55:00:33.4 |
HIP 16941 |
12.27 |
| 2026-10-05 12:00 |
03:38:48.33 |
+55:00:47.0 |
HIP 16941 |
11.64 |
| 2026-10-06 00:00 |
03:38:43.02 |
+55:01:00.3 |
HIP 16941 |
11.03 |
| 2026-10-06 12:00 |
03:38:37.66 |
+55:01:13.3 |
HIP 16941 |
10.44 |
| 2026-10-07 00:00 |
03:38:32.25 |
+55:01:25.9 |
HIP 16941 |
9.89 |
| 2026-10-07 12:00 |
03:38:26.80 |
+55:01:38.2 |
HIP 16941 |
9.37 |
| 2026-10-08 00:00 |
03:38:21.29 |
+55:01:50.1 |
HIP 16941 |
8.90 |
| 2026-10-08 12:00 |
03:38:15.74 |
+55:02:01.8 |
HIP 16941 |
8.49 |
| 2026-10-09 00:00 |
03:38:10.15 |
+55:02:13.0 |
HIP 16941 |
8.14 |
| 2026-10-09 12:00 |
03:38:04.50 |
+55:02:24.0 |
HIP 16941 |
7.87 |
| 2026-10-10 00:00 |
03:37:58.81 |
+55:02:34.6 |
HIP 16941 |
7.68 |
| 2026-10-10 12:00 |
03:37:53.08 |
+55:02:44.8 |
HIP 16941 |
7.59 |
| 2026-10-11 00:00 |
03:37:47.30 |
+55:02:54.7 |
HIP 16941 |
7.60 |