| Parameter |
Value |
| Designation |
C/2015 K7 (COIAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2013-02-19T19:51:17.665920Z |
| Orbit solution date (soln_date, UTC) |
2024-12-23T14:42:02Z |
| Obs used |
59 |
| NEO |
- |
| M1 |
7.400 |
| K1 |
10.250 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2015-05-17T09:45:54.432000Z |
| Discovery magnitude (MPC) |
23.40 g |
| Discovery observatory (MPC) |
T09 · Subaru Telescope, Maunakea |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2014-08-27.0000000 |
| e |
1.00398018 |
| q (au) |
9.940926 |
| a (au) |
-2497.604954 |
| i (deg) |
159.939165 |
| Ω (om, deg) |
258.001127 |
| ω (w, deg) |
5.158803 |
| M (ma, deg) |
0.004368 |
Magnitude
Scatter + Global Linear
$$
M_a = (5.606 + 4.567\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
5.606 |
| n |
4.567 |
| gf |
0.823 |
| gb |
-1.000 |
| k |
1.000 |
| δ90 |
6.217 |
| 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) |
| 2026-06-01 00:00 |
10:26:17.89 |
+30:09:49.8 |
HIP 50997 |
20.65 |
| 2026-06-01 12:00 |
10:26:17.47 |
+30:09:27.0 |
HIP 50997 |
20.81 |
| 2026-06-02 00:00 |
10:26:17.08 |
+30:09:04.1 |
HIP 50997 |
20.99 |
| 2026-06-02 12:00 |
10:26:16.75 |
+30:08:40.9 |
HIP 50997 |
21.18 |
| 2026-06-03 00:00 |
10:26:16.45 |
+30:08:17.6 |
HIP 50997 |
21.38 |
| 2026-06-03 12:00 |
10:26:16.19 |
+30:07:54.2 |
HIP 50997 |
21.60 |
| 2026-06-04 00:00 |
10:26:15.98 |
+30:07:30.6 |
HIP 50997 |
21.83 |
| 2026-06-04 12:00 |
10:26:15.80 |
+30:07:06.9 |
HIP 50997 |
22.07 |
| 2026-06-05 00:00 |
10:26:15.67 |
+30:06:43.0 |
HIP 50997 |
22.33 |
| 2026-06-05 12:00 |
10:26:15.58 |
+30:06:19.0 |
HIP 50997 |
22.59 |
| 2026-06-06 00:00 |
10:26:15.53 |
+30:05:54.8 |
HIP 50997 |
22.87 |
| 2026-06-06 12:00 |
10:26:15.52 |
+30:05:30.5 |
HIP 50997 |
23.16 |
| 2026-06-07 00:00 |
10:26:15.55 |
+30:05:06.0 |
HIP 50997 |
23.47 |
| 2026-06-07 12:00 |
10:26:15.62 |
+30:04:41.4 |
HIP 50997 |
23.78 |
| 2026-06-08 00:00 |
10:26:15.74 |
+30:04:16.7 |
HIP 50997 |
24.10 |
| 2026-06-08 12:00 |
10:26:15.89 |
+30:03:51.8 |
HIP 50997 |
24.44 |
| 2026-06-09 00:00 |
10:26:16.08 |
+30:03:26.8 |
HIP 50997 |
24.78 |
| 2026-06-09 12:00 |
10:26:16.32 |
+30:03:01.7 |
HIP 51158 |
24.39 |
| 2026-06-10 00:00 |
10:26:16.59 |
+30:02:36.4 |
HIP 51158 |
23.97 |
| 2026-06-10 12:00 |
10:26:16.90 |
+30:02:11.1 |
HIP 51158 |
23.56 |
| 2026-06-11 00:00 |
10:26:17.26 |
+30:01:45.6 |
HIP 51158 |
23.14 |
| 2026-06-11 12:00 |
10:26:17.65 |
+30:01:19.9 |
HIP 51158 |
22.71 |
| 2026-06-12 00:00 |
10:26:18.08 |
+30:00:54.2 |
HIP 51158 |
22.28 |
| 2026-06-12 12:00 |
10:26:18.56 |
+30:00:28.3 |
HIP 51158 |
21.85 |
| 2026-06-13 00:00 |
10:26:19.07 |
+30:00:02.3 |
HIP 51158 |
21.41 |
| 2026-06-13 12:00 |
10:26:19.62 |
+29:59:36.2 |
HIP 51158 |
20.96 |
| 2026-06-14 00:00 |
10:26:20.21 |
+29:59:10.0 |
HIP 51158 |
20.51 |
| 2026-06-14 12:00 |
10:26:20.84 |
+29:58:43.7 |
HIP 51158 |
20.05 |
| 2026-06-15 00:00 |
10:26:21.51 |
+29:58:17.3 |
HIP 51158 |
19.59 |
| 2026-06-15 12:00 |
10:26:22.21 |
+29:57:50.8 |
HIP 51158 |
19.13 |
| 2026-06-16 00:00 |
10:26:22.96 |
+29:57:24.1 |
HIP 51158 |
18.66 |
| 2026-06-16 12:00 |
10:26:23.74 |
+29:56:57.4 |
HIP 51158 |
18.18 |
| 2026-06-17 00:00 |
10:26:24.56 |
+29:56:30.6 |
HIP 51158 |
17.70 |
| 2026-06-17 12:00 |
10:26:25.42 |
+29:56:03.6 |
HIP 51158 |
17.22 |
| 2026-06-18 00:00 |
10:26:26.32 |
+29:55:36.6 |
HIP 51158 |
16.73 |
| 2026-06-18 12:00 |
10:26:27.25 |
+29:55:09.5 |
HIP 51158 |
16.23 |
| 2026-06-19 00:00 |
10:26:28.23 |
+29:54:42.3 |
HIP 51158 |
15.73 |
| 2026-06-19 12:00 |
10:26:29.23 |
+29:54:15.0 |
HIP 51158 |
15.23 |
| 2026-06-20 00:00 |
10:26:30.28 |
+29:53:47.7 |
HIP 51158 |
14.72 |
| 2026-06-20 12:00 |
10:26:31.36 |
+29:53:20.2 |
HIP 51158 |
14.20 |
| 2026-06-21 00:00 |
10:26:32.48 |
+29:52:52.7 |
HIP 51158 |
13.69 |
| 2026-06-21 12:00 |
10:26:33.64 |
+29:52:25.1 |
HIP 51158 |
13.16 |
| 2026-06-22 00:00 |
10:26:34.83 |
+29:51:57.4 |
HIP 51158 |
12.64 |