| 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
$$
M_a = (12.555 + 3.942\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.555 |
| n |
3.942 |
| gf |
0.994 |
| 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) |
| 2026-09-20 00:00 |
23:57:11.62 |
-20:46:05.9 |
HIP 118081 |
3.93 |
| 2026-09-20 12:00 |
23:57:10.33 |
-20:46:13.4 |
HIP 118081 |
3.79 |
| 2026-09-21 00:00 |
23:57:09.05 |
-20:46:20.8 |
HIP 118081 |
3.68 |
| 2026-09-21 12:00 |
23:57:07.76 |
-20:46:28.2 |
HIP 118081 |
3.59 |
| 2026-09-22 00:00 |
23:57:06.47 |
-20:46:35.5 |
HIP 118081 |
3.53 |
| 2026-09-22 12:00 |
23:57:05.19 |
-20:46:42.8 |
HIP 118081 |
3.50 |
| 2026-09-23 00:00 |
23:57:03.90 |
-20:46:50.0 |
HIP 118081 |
3.50 |
| 2026-09-23 12:00 |
23:57:02.62 |
-20:46:57.1 |
HIP 118081 |
3.53 |
| 2026-09-24 00:00 |
23:57:01.33 |
-20:47:04.2 |
HIP 118081 |
3.59 |
| 2026-09-24 12:00 |
23:57:00.05 |
-20:47:11.2 |
HIP 118081 |
3.68 |
| 2026-09-25 00:00 |
23:56:58.76 |
-20:47:18.2 |
HIP 118081 |
3.80 |
| 2026-09-25 12:00 |
23:56:57.48 |
-20:47:25.0 |
HIP 118081 |
3.94 |
| 2026-09-26 00:00 |
23:56:56.19 |
-20:47:31.9 |
HIP 118081 |
4.10 |
| 2026-09-26 12:00 |
23:56:54.91 |
-20:47:38.6 |
HIP 118081 |
4.28 |
| 2026-09-27 00:00 |
23:56:53.63 |
-20:47:45.3 |
HIP 118081 |
4.47 |
| 2026-09-27 12:00 |
23:56:52.35 |
-20:47:52.0 |
HIP 118081 |
4.68 |
| 2026-09-28 00:00 |
23:56:51.07 |
-20:47:58.5 |
HIP 118081 |
4.90 |
| 2026-09-28 12:00 |
23:56:49.79 |
-20:48:05.0 |
HIP 118081 |
5.13 |
| 2026-09-29 00:00 |
23:56:48.51 |
-20:48:11.4 |
HIP 118081 |
5.37 |
| 2026-09-29 12:00 |
23:56:47.23 |
-20:48:17.8 |
HIP 118081 |
5.62 |
| 2026-09-30 00:00 |
23:56:45.96 |
-20:48:24.1 |
HIP 118081 |
5.88 |
| 2026-09-30 12:00 |
23:56:44.69 |
-20:48:30.3 |
HIP 118081 |
6.14 |
| 2026-10-01 00:00 |
23:56:43.41 |
-20:48:36.5 |
HIP 118081 |
6.40 |
| 2026-10-01 12:00 |
23:56:42.14 |
-20:48:42.6 |
HIP 118081 |
6.67 |
| 2026-10-02 00:00 |
23:56:40.87 |
-20:48:48.6 |
HIP 118081 |
6.94 |
| 2026-10-02 12:00 |
23:56:39.61 |
-20:48:54.5 |
HIP 118081 |
7.22 |
| 2026-10-03 00:00 |
23:56:38.34 |
-20:49:00.4 |
HIP 118081 |
7.50 |
| 2026-10-03 12:00 |
23:56:37.08 |
-20:49:06.2 |
HIP 118081 |
7.78 |
| 2026-10-04 00:00 |
23:56:35.82 |
-20:49:12.0 |
HIP 118081 |
8.06 |
| 2026-10-04 12:00 |
23:56:34.56 |
-20:49:17.6 |
HIP 118081 |
8.34 |
| 2026-10-05 00:00 |
23:56:33.31 |
-20:49:23.2 |
HIP 118081 |
8.63 |
| 2026-10-05 12:00 |
23:56:32.05 |
-20:49:28.7 |
HIP 118081 |
8.91 |
| 2026-10-06 00:00 |
23:56:30.80 |
-20:49:34.2 |
HIP 118081 |
9.20 |
| 2026-10-06 12:00 |
23:56:29.55 |
-20:49:39.5 |
HIP 118081 |
9.49 |
| 2026-10-07 00:00 |
23:56:28.31 |
-20:49:44.8 |
HIP 118081 |
9.78 |
| 2026-10-07 12:00 |
23:56:27.06 |
-20:49:50.0 |
HIP 118081 |
10.07 |
| 2026-10-08 00:00 |
23:56:25.82 |
-20:49:55.2 |
HIP 118081 |
10.35 |
| 2026-10-08 12:00 |
23:56:24.59 |
-20:50:00.2 |
HIP 118081 |
10.64 |
| 2026-10-09 00:00 |
23:56:23.35 |
-20:50:05.2 |
HIP 118081 |
10.93 |
| 2026-10-09 12:00 |
23:56:22.12 |
-20:50:10.1 |
HIP 118081 |
11.22 |
| 2026-10-10 00:00 |
23:56:20.90 |
-20:50:14.9 |
HIP 118081 |
11.51 |
| 2026-10-10 12:00 |
23:56:19.67 |
-20:50:19.7 |
HIP 118081 |
11.79 |
| 2026-10-11 00:00 |
23:56:18.45 |
-20:50:24.4 |
HIP 118081 |
12.08 |