| Parameter |
Value |
| Designation |
C/2021 K2 (MASTER) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2021-09-09T03:37:31.964160Z |
| Orbit solution date (soln_date, UTC) |
2022-07-16T01:42:47Z |
| Obs used |
80 |
| NEO |
- |
| M1 |
8.000 |
| K1 |
10.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2021-05-22T23:28:21.792000Z |
| Discovery magnitude (MPC) |
18.70 R |
| Discovery observatory (MPC) |
K95 · MASTER-SAAO Observatory, Sutherland |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2021-10-19.0000000 |
| e |
1.00120074 |
| q (au) |
5.467026 |
| a (au) |
-4553.055334 |
| i (deg) |
100.845478 |
| Ω (om, deg) |
282.245058 |
| ω (w, deg) |
343.321986 |
| M (ma, deg) |
0.000128 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.806 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.806 |
| n |
2.000 |
| gf |
0.998 |
| gb |
-1.000 |
| 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) |
| 2026-06-01 00:00 |
17:04:33.56 |
+58:56:13.2 |
HIP 83654 |
10.15 |
| 2026-06-01 12:00 |
17:04:13.48 |
+58:57:03.1 |
HIP 83654 |
12.80 |
| 2026-06-02 00:00 |
17:03:53.38 |
+58:57:51.6 |
HIP 83654 |
15.47 |
| 2026-06-02 12:00 |
17:03:33.26 |
+58:58:38.8 |
HIP 83654 |
18.15 |
| 2026-06-03 00:00 |
17:03:13.13 |
+58:59:24.6 |
HIP 83654 |
20.84 |
| 2026-06-03 12:00 |
17:02:52.97 |
+59:00:08.9 |
HIP 83654 |
23.52 |
| 2026-06-04 00:00 |
17:02:32.80 |
+59:00:51.9 |
HIP 83654 |
26.21 |
| 2026-06-04 12:00 |
17:02:12.62 |
+59:01:33.5 |
HIP 83305 |
28.68 |
| 2026-06-05 00:00 |
17:01:52.42 |
+59:02:13.7 |
HIP 83305 |
28.98 |
| 2026-06-05 12:00 |
17:01:32.22 |
+59:02:52.6 |
HIP 83305 |
29.49 |
| 2026-06-06 00:00 |
17:01:12.01 |
+59:03:30.0 |
HIP 83160 |
29.96 |
| 2026-06-06 12:00 |
17:00:51.79 |
+59:04:06.0 |
HIP 83160 |
29.62 |
| 2026-06-07 00:00 |
17:00:31.57 |
+59:04:40.7 |
HIP 83160 |
29.50 |
| 2026-06-07 12:00 |
17:00:11.35 |
+59:05:13.9 |
HIP 83160 |
29.60 |
| 2026-06-08 00:00 |
16:59:51.13 |
+59:05:45.8 |
HIP 83160 |
29.92 |
| 2026-06-08 12:00 |
16:59:30.92 |
+59:06:16.3 |
HIP 82966 |
29.73 |
| 2026-06-09 00:00 |
16:59:10.70 |
+59:06:45.4 |
HIP 82966 |
27.90 |
| 2026-06-09 12:00 |
16:58:50.50 |
+59:07:13.1 |
HIP 82966 |
26.22 |
| 2026-06-10 00:00 |
16:58:30.30 |
+59:07:39.4 |
HIP 82966 |
24.73 |
| 2026-06-10 12:00 |
16:58:10.11 |
+59:08:04.3 |
HIP 82966 |
23.46 |
| 2026-06-11 00:00 |
16:57:49.94 |
+59:08:27.9 |
HIP 82966 |
22.45 |
| 2026-06-11 12:00 |
16:57:29.78 |
+59:08:50.0 |
HIP 82966 |
21.73 |
| 2026-06-12 00:00 |
16:57:09.63 |
+59:09:10.8 |
HIP 82966 |
21.32 |
| 2026-06-12 12:00 |
16:56:49.51 |
+59:09:30.2 |
HIP 82966 |
21.25 |
| 2026-06-13 00:00 |
16:56:29.40 |
+59:09:48.2 |
HIP 82966 |
21.52 |
| 2026-06-13 12:00 |
16:56:09.32 |
+59:10:04.9 |
HIP 82966 |
22.10 |
| 2026-06-14 00:00 |
16:55:49.26 |
+59:10:20.2 |
HIP 82966 |
22.98 |
| 2026-06-14 12:00 |
16:55:29.23 |
+59:10:34.1 |
HIP 82966 |
24.11 |
| 2026-06-15 00:00 |
16:55:09.23 |
+59:10:46.6 |
HIP 82966 |
25.47 |
| 2026-06-15 12:00 |
16:54:49.26 |
+59:10:57.8 |
HIP 82508 |
24.33 |
| 2026-06-16 00:00 |
16:54:29.33 |
+59:11:07.6 |
HIP 82508 |
21.87 |
| 2026-06-16 12:00 |
16:54:09.42 |
+59:11:16.0 |
HIP 82508 |
19.44 |
| 2026-06-17 00:00 |
16:53:49.56 |
+59:11:23.1 |
HIP 82508 |
17.07 |
| 2026-06-17 12:00 |
16:53:29.73 |
+59:11:28.9 |
HIP 82508 |
14.76 |
| 2026-06-18 00:00 |
16:53:09.95 |
+59:11:33.3 |
HIP 82508 |
12.57 |
| 2026-06-18 12:00 |
16:52:50.21 |
+59:11:36.3 |
HIP 82508 |
10.55 |
| 2026-06-19 00:00 |
16:52:30.51 |
+59:11:38.1 |
HIP 82508 |
8.80 |
| 2026-06-19 12:00 |
16:52:10.86 |
+59:11:38.5 |
HIP 82508 |
7.54 |
| 2026-06-20 00:00 |
16:51:51.26 |
+59:11:37.6 |
HIP 82508 |
7.01 |
| 2026-06-20 12:00 |
16:51:31.71 |
+59:11:35.3 |
HIP 82508 |
7.36 |
| 2026-06-21 00:00 |
16:51:12.22 |
+59:11:31.8 |
HIP 82508 |
8.49 |
| 2026-06-21 12:00 |
16:50:52.77 |
+59:11:26.9 |
HIP 82508 |
10.13 |
| 2026-06-22 00:00 |
16:50:33.39 |
+59:11:20.8 |
HIP 82508 |
12.06 |