| 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) |
| 2026-09-25 00:00 |
10:36:32.31 |
+28:38:55.8 |
HIP 52008 |
24.28 |
| 2026-09-25 12:00 |
10:36:35.70 |
+28:38:48.1 |
HIP 52008 |
23.79 |
| 2026-09-26 00:00 |
10:36:39.08 |
+28:38:40.6 |
HIP 52008 |
23.31 |
| 2026-09-26 12:00 |
10:36:42.44 |
+28:38:33.3 |
HIP 52008 |
22.85 |
| 2026-09-27 00:00 |
10:36:45.78 |
+28:38:26.3 |
HIP 52008 |
22.41 |
| 2026-09-27 12:00 |
10:36:49.10 |
+28:38:19.6 |
HIP 52008 |
22.00 |
| 2026-09-28 00:00 |
10:36:52.41 |
+28:38:13.1 |
HIP 52008 |
21.60 |
| 2026-09-28 12:00 |
10:36:55.70 |
+28:38:06.9 |
HIP 52008 |
21.23 |
| 2026-09-29 00:00 |
10:36:58.98 |
+28:38:00.9 |
HIP 52008 |
20.89 |
| 2026-09-29 12:00 |
10:37:02.23 |
+28:37:55.2 |
HIP 52008 |
20.57 |
| 2026-09-30 00:00 |
10:37:05.47 |
+28:37:49.8 |
HIP 52008 |
20.28 |
| 2026-09-30 12:00 |
10:37:08.68 |
+28:37:44.6 |
HIP 52008 |
20.01 |
| 2026-10-01 00:00 |
10:37:11.88 |
+28:37:39.6 |
HIP 52008 |
19.77 |
| 2026-10-01 12:00 |
10:37:15.06 |
+28:37:35.0 |
HIP 52008 |
19.56 |
| 2026-10-02 00:00 |
10:37:18.22 |
+28:37:30.6 |
HIP 52008 |
19.37 |
| 2026-10-02 12:00 |
10:37:21.36 |
+28:37:26.4 |
HIP 52008 |
19.22 |
| 2026-10-03 00:00 |
10:37:24.48 |
+28:37:22.6 |
HIP 52008 |
19.09 |
| 2026-10-03 12:00 |
10:37:27.58 |
+28:37:19.0 |
HIP 52008 |
18.99 |
| 2026-10-04 00:00 |
10:37:30.66 |
+28:37:15.6 |
HIP 52008 |
18.92 |
| 2026-10-04 12:00 |
10:37:33.72 |
+28:37:12.5 |
HIP 52008 |
18.88 |
| 2026-10-05 00:00 |
10:37:36.75 |
+28:37:09.7 |
HIP 52008 |
18.87 |
| 2026-10-05 12:00 |
10:37:39.77 |
+28:37:07.2 |
HIP 52008 |
18.88 |
| 2026-10-06 00:00 |
10:37:42.76 |
+28:37:05.0 |
HIP 52008 |
18.93 |
| 2026-10-06 12:00 |
10:37:45.73 |
+28:37:03.0 |
HIP 52008 |
18.99 |
| 2026-10-07 00:00 |
10:37:48.68 |
+28:37:01.3 |
HIP 52008 |
19.09 |
| 2026-10-07 12:00 |
10:37:51.60 |
+28:36:59.8 |
HIP 52008 |
19.21 |
| 2026-10-08 00:00 |
10:37:54.51 |
+28:36:58.7 |
HIP 52008 |
19.35 |
| 2026-10-08 12:00 |
10:37:57.39 |
+28:36:57.8 |
HIP 52008 |
19.51 |
| 2026-10-09 00:00 |
10:38:00.24 |
+28:36:57.2 |
HIP 52008 |
19.70 |
| 2026-10-09 12:00 |
10:38:03.07 |
+28:36:56.8 |
HIP 52008 |
19.91 |
| 2026-10-10 00:00 |
10:38:05.88 |
+28:36:56.8 |
HIP 52008 |
20.14 |
| 2026-10-10 12:00 |
10:38:08.66 |
+28:36:57.0 |
HIP 52170 |
19.71 |
| 2026-10-11 00:00 |
10:38:11.42 |
+28:36:57.5 |
HIP 52170 |
19.16 |
| 2026-10-11 12:00 |
10:38:14.15 |
+28:36:58.3 |
HIP 52170 |
18.62 |
| 2026-10-12 00:00 |
10:38:16.86 |
+28:36:59.4 |
HIP 52170 |
18.08 |
| 2026-10-12 12:00 |
10:38:19.54 |
+28:37:00.7 |
HIP 52170 |
17.54 |
| 2026-10-13 00:00 |
10:38:22.19 |
+28:37:02.4 |
HIP 52170 |
17.01 |
| 2026-10-13 12:00 |
10:38:24.82 |
+28:37:04.3 |
HIP 52170 |
16.49 |
| 2026-10-14 00:00 |
10:38:27.42 |
+28:37:06.5 |
HIP 52170 |
15.98 |
| 2026-10-14 12:00 |
10:38:30.00 |
+28:37:09.0 |
HIP 52170 |
15.47 |
| 2026-10-15 00:00 |
10:38:32.55 |
+28:37:11.7 |
HIP 52170 |
14.97 |
| 2026-10-15 12:00 |
10:38:35.07 |
+28:37:14.8 |
HIP 52170 |
14.47 |
| 2026-10-16 00:00 |
10:38:37.56 |
+28:37:18.1 |
HIP 52170 |
13.99 |