| Parameter |
Value |
| Designation |
C/1959 X1 (Mrkos) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1959-11-13T05:29:53.125440Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:14Z |
| Obs used |
19 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1960-05-18.0000000 |
| e |
0.99998877 |
| q (au) |
1.253241 |
| a (au) |
111604.932920 |
| i (deg) |
19.636163 |
| Ω (om, deg) |
100.618812 |
| ω (w, deg) |
84.688954 |
| M (ma, deg) |
0.000005 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.553 + 3.942\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.553 |
| n |
3.942 |
| gf |
0.995 |
| gb |
-0.680 |
| k |
0.811 |
| 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) |
| 2026-05-12 00:00 |
23:58:58.09 |
-20:13:56.2 |
HIP 118181 |
9.87 |
| 2026-05-12 12:00 |
23:58:58.92 |
-20:13:56.6 |
HIP 118181 |
10.03 |
| 2026-05-13 00:00 |
23:58:59.75 |
-20:13:57.2 |
HIP 118181 |
10.19 |
| 2026-05-13 12:00 |
23:59:00.56 |
-20:13:57.9 |
HIP 118181 |
10.35 |
| 2026-05-14 00:00 |
23:59:01.37 |
-20:13:58.6 |
HIP 118181 |
10.51 |
| 2026-05-14 12:00 |
23:59:02.17 |
-20:13:59.4 |
HIP 118181 |
10.67 |
| 2026-05-15 00:00 |
23:59:02.96 |
-20:14:00.4 |
HIP 118181 |
10.83 |
| 2026-05-15 12:00 |
23:59:03.75 |
-20:14:01.3 |
HIP 118181 |
10.98 |
| 2026-05-16 00:00 |
23:59:04.52 |
-20:14:02.4 |
HIP 118181 |
11.13 |
| 2026-05-16 12:00 |
23:59:05.28 |
-20:14:03.6 |
HIP 118181 |
11.28 |
| 2026-05-17 00:00 |
23:59:06.04 |
-20:14:04.8 |
HIP 118181 |
11.43 |
| 2026-05-17 12:00 |
23:59:06.79 |
-20:14:06.2 |
HIP 118181 |
11.58 |
| 2026-05-18 00:00 |
23:59:07.52 |
-20:14:07.6 |
HIP 118181 |
11.73 |
| 2026-05-18 12:00 |
23:59:08.25 |
-20:14:09.1 |
HIP 118181 |
11.87 |
| 2026-05-19 00:00 |
23:59:08.97 |
-20:14:10.7 |
HIP 118181 |
12.01 |
| 2026-05-19 12:00 |
23:59:09.68 |
-20:14:12.4 |
HIP 118181 |
12.15 |
| 2026-05-20 00:00 |
23:59:10.38 |
-20:14:14.1 |
HIP 118181 |
12.29 |
| 2026-05-20 12:00 |
23:59:11.07 |
-20:14:15.9 |
HIP 118181 |
12.43 |
| 2026-05-21 00:00 |
23:59:11.76 |
-20:14:17.9 |
HIP 118181 |
12.57 |
| 2026-05-21 12:00 |
23:59:12.43 |
-20:14:19.9 |
HIP 118181 |
12.70 |
| 2026-05-22 00:00 |
23:59:13.09 |
-20:14:22.0 |
HIP 118278 |
12.82 |
| 2026-05-22 12:00 |
23:59:13.75 |
-20:14:24.1 |
HIP 118278 |
12.81 |
| 2026-05-23 00:00 |
23:59:14.39 |
-20:14:26.4 |
HIP 118278 |
12.81 |
| 2026-05-23 12:00 |
23:59:15.03 |
-20:14:28.7 |
HIP 118278 |
12.81 |
| 2026-05-24 00:00 |
23:59:15.65 |
-20:14:31.1 |
HIP 118278 |
12.82 |
| 2026-05-24 12:00 |
23:59:16.27 |
-20:14:33.6 |
HIP 118278 |
12.82 |
| 2026-05-25 00:00 |
23:59:16.88 |
-20:14:36.2 |
HIP 118278 |
12.84 |
| 2026-05-25 12:00 |
23:59:17.47 |
-20:14:38.9 |
HIP 118278 |
12.85 |
| 2026-05-26 00:00 |
23:59:18.06 |
-20:14:41.6 |
HIP 118278 |
12.87 |
| 2026-05-26 12:00 |
23:59:18.64 |
-20:14:44.4 |
HIP 118278 |
12.89 |
| 2026-05-27 00:00 |
23:59:19.20 |
-20:14:47.3 |
HIP 118278 |
12.92 |
| 2026-05-27 12:00 |
23:59:19.76 |
-20:14:50.3 |
HIP 118278 |
12.95 |
| 2026-05-28 00:00 |
23:59:20.31 |
-20:14:53.4 |
HIP 118278 |
12.98 |
| 2026-05-28 12:00 |
23:59:20.85 |
-20:14:56.5 |
HIP 118278 |
13.01 |
| 2026-05-29 00:00 |
23:59:21.38 |
-20:14:59.8 |
HIP 118278 |
13.05 |
| 2026-05-29 12:00 |
23:59:21.89 |
-20:15:03.1 |
HIP 118278 |
13.09 |
| 2026-05-30 00:00 |
23:59:22.40 |
-20:15:06.4 |
HIP 118278 |
13.13 |
| 2026-05-30 12:00 |
23:59:22.90 |
-20:15:09.9 |
HIP 118278 |
13.18 |
| 2026-05-31 00:00 |
23:59:23.39 |
-20:15:13.4 |
HIP 118278 |
13.23 |
| 2026-05-31 12:00 |
23:59:23.87 |
-20:15:17.1 |
HIP 118278 |
13.28 |
| 2026-06-01 00:00 |
23:59:24.34 |
-20:15:20.7 |
HIP 118278 |
13.33 |
| 2026-06-01 12:00 |
23:59:24.79 |
-20:15:24.5 |
HIP 118278 |
13.39 |
| 2026-06-02 00:00 |
23:59:25.24 |
-20:15:28.4 |
HIP 118278 |
13.45 |