| 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) |
| 2026-05-12 00:00 |
03:26:35.56 |
+52:54:48.2 |
HIP 15976 |
12.46 |
| 2026-05-12 12:00 |
03:26:42.84 |
+52:54:55.2 |
HIP 15976 |
13.27 |
| 2026-05-13 00:00 |
03:26:50.12 |
+52:55:02.5 |
HIP 15976 |
14.12 |
| 2026-05-13 12:00 |
03:26:57.41 |
+52:55:10.0 |
HIP 15976 |
15.00 |
| 2026-05-14 00:00 |
03:27:04.69 |
+52:55:17.9 |
HIP 15976 |
15.92 |
| 2026-05-14 12:00 |
03:27:11.97 |
+52:55:26.0 |
HIP 15976 |
16.86 |
| 2026-05-15 00:00 |
03:27:19.26 |
+52:55:34.4 |
HIP 15976 |
17.83 |
| 2026-05-15 12:00 |
03:27:26.54 |
+52:55:43.1 |
HIP 15976 |
18.81 |
| 2026-05-16 00:00 |
03:27:33.82 |
+52:55:52.1 |
HIP 15976 |
19.81 |
| 2026-05-16 12:00 |
03:27:41.10 |
+52:56:01.3 |
HIP 15976 |
20.82 |
| 2026-05-17 00:00 |
03:27:48.38 |
+52:56:10.8 |
HIP 15976 |
21.85 |
| 2026-05-17 12:00 |
03:27:55.66 |
+52:56:20.7 |
HIP 16316 |
21.57 |
| 2026-05-18 00:00 |
03:28:02.93 |
+52:56:30.8 |
HIP 16316 |
20.51 |
| 2026-05-18 12:00 |
03:28:10.20 |
+52:56:41.1 |
HIP 16316 |
19.45 |
| 2026-05-19 00:00 |
03:28:17.46 |
+52:56:51.8 |
HIP 16316 |
18.40 |
| 2026-05-19 12:00 |
03:28:24.72 |
+52:57:02.7 |
HIP 16316 |
17.35 |
| 2026-05-20 00:00 |
03:28:31.98 |
+52:57:13.9 |
HIP 16316 |
16.32 |
| 2026-05-20 12:00 |
03:28:39.23 |
+52:57:25.4 |
HIP 16316 |
15.30 |
| 2026-05-21 00:00 |
03:28:46.48 |
+52:57:37.1 |
HIP 16316 |
14.29 |
| 2026-05-21 12:00 |
03:28:53.72 |
+52:57:49.1 |
HIP 16316 |
13.31 |
| 2026-05-22 00:00 |
03:29:00.95 |
+52:58:01.4 |
HIP 16316 |
12.35 |
| 2026-05-22 12:00 |
03:29:08.18 |
+52:58:13.9 |
HIP 16316 |
11.41 |
| 2026-05-23 00:00 |
03:29:15.40 |
+52:58:26.8 |
HIP 16316 |
10.52 |
| 2026-05-23 12:00 |
03:29:22.61 |
+52:58:39.8 |
HIP 16316 |
9.67 |
| 2026-05-24 00:00 |
03:29:29.81 |
+52:58:53.2 |
HIP 16316 |
8.89 |
| 2026-05-24 12:00 |
03:29:37.01 |
+52:59:06.8 |
HIP 16316 |
8.18 |
| 2026-05-25 00:00 |
03:29:44.19 |
+52:59:20.6 |
HIP 16316 |
7.57 |
| 2026-05-25 12:00 |
03:29:51.37 |
+52:59:34.7 |
HIP 16316 |
7.10 |
| 2026-05-26 00:00 |
03:29:58.54 |
+52:59:49.1 |
HIP 16316 |
6.77 |
| 2026-05-26 12:00 |
03:30:05.69 |
+53:00:03.7 |
HIP 16316 |
6.62 |
| 2026-05-27 00:00 |
03:30:12.84 |
+53:00:18.6 |
HIP 16316 |
6.66 |
| 2026-05-27 12:00 |
03:30:19.98 |
+53:00:33.7 |
HIP 16316 |
6.88 |
| 2026-05-28 00:00 |
03:30:27.10 |
+53:00:49.1 |
HIP 16316 |
7.26 |
| 2026-05-28 12:00 |
03:30:34.21 |
+53:01:04.7 |
HIP 16316 |
7.79 |
| 2026-05-29 00:00 |
03:30:41.32 |
+53:01:20.6 |
HIP 16316 |
8.44 |
| 2026-05-29 12:00 |
03:30:48.41 |
+53:01:36.8 |
HIP 16316 |
9.17 |
| 2026-05-30 00:00 |
03:30:55.48 |
+53:01:53.1 |
HIP 16316 |
9.98 |
| 2026-05-30 12:00 |
03:31:02.55 |
+53:02:09.8 |
HIP 16316 |
10.83 |
| 2026-05-31 00:00 |
03:31:09.59 |
+53:02:26.6 |
HIP 16316 |
11.73 |
| 2026-05-31 12:00 |
03:31:16.63 |
+53:02:43.7 |
HIP 16316 |
12.66 |
| 2026-06-01 00:00 |
03:31:23.65 |
+53:03:01.1 |
HIP 16316 |
13.62 |
| 2026-06-01 12:00 |
03:31:30.66 |
+53:03:18.7 |
HIP 16316 |
14.60 |
| 2026-06-02 00:00 |
03:31:37.65 |
+53:03:36.5 |
HIP 16316 |
15.60 |