| Parameter |
Value |
| Designation |
C/1956 E1 (Mrkos) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1956-04-13T14:37:14.880000Z |
| Orbit solution date (soln_date, UTC) |
- |
| Obs used |
32 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1956-04-13.6092000 |
| e |
1.00000000 |
| q (au) |
0.842240 |
| a (au) |
- |
| i (deg) |
147.451900 |
| Ω (om, deg) |
226.715900 |
| ω (w, deg) |
81.001500 |
| M (ma, deg) |
- |
Magnitude
Scatter + Global Linear
$$
M_a = (9.975 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.975 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.938 |
| 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 |
23:40:00.29 |
-35:58:32.6 |
HIP 116910 |
23.05 |
| 2026-09-20 12:00 |
23:39:58.86 |
-35:58:38.4 |
HIP 116910 |
23.34 |
| 2026-09-21 00:00 |
23:39:57.42 |
-35:58:44.0 |
HIP 116910 |
23.63 |
| 2026-09-21 12:00 |
23:39:55.99 |
-35:58:49.5 |
HIP 116910 |
23.92 |
| 2026-09-22 00:00 |
23:39:54.56 |
-35:58:54.9 |
HIP 116614 |
24.14 |
| 2026-09-22 12:00 |
23:39:53.13 |
-35:59:00.3 |
HIP 116614 |
23.88 |
| 2026-09-23 00:00 |
23:39:51.70 |
-35:59:05.5 |
HIP 116614 |
23.63 |
| 2026-09-23 12:00 |
23:39:50.27 |
-35:59:10.7 |
HIP 116614 |
23.37 |
| 2026-09-24 00:00 |
23:39:48.84 |
-35:59:15.7 |
HIP 116614 |
23.12 |
| 2026-09-24 12:00 |
23:39:47.41 |
-35:59:20.7 |
HIP 116614 |
22.86 |
| 2026-09-25 00:00 |
23:39:45.99 |
-35:59:25.6 |
HIP 116614 |
22.61 |
| 2026-09-25 12:00 |
23:39:44.57 |
-35:59:30.3 |
HIP 116614 |
22.36 |
| 2026-09-26 00:00 |
23:39:43.14 |
-35:59:35.0 |
HIP 116614 |
22.11 |
| 2026-09-26 12:00 |
23:39:41.72 |
-35:59:39.6 |
HIP 116614 |
21.86 |
| 2026-09-27 00:00 |
23:39:40.31 |
-35:59:44.0 |
HIP 116614 |
21.61 |
| 2026-09-27 12:00 |
23:39:38.89 |
-35:59:48.4 |
HIP 116614 |
21.37 |
| 2026-09-28 00:00 |
23:39:37.48 |
-35:59:52.7 |
HIP 116614 |
21.12 |
| 2026-09-28 12:00 |
23:39:36.07 |
-35:59:56.9 |
HIP 116614 |
20.88 |
| 2026-09-29 00:00 |
23:39:34.66 |
-36:00:01.0 |
HIP 116614 |
20.63 |
| 2026-09-29 12:00 |
23:39:33.25 |
-36:00:04.9 |
HIP 116614 |
20.39 |
| 2026-09-30 00:00 |
23:39:31.84 |
-36:00:08.8 |
HIP 116614 |
20.15 |
| 2026-09-30 12:00 |
23:39:30.44 |
-36:00:12.6 |
HIP 116614 |
19.91 |
| 2026-10-01 00:00 |
23:39:29.04 |
-36:00:16.3 |
HIP 116614 |
19.67 |
| 2026-10-01 12:00 |
23:39:27.65 |
-36:00:19.9 |
HIP 116614 |
19.43 |
| 2026-10-02 00:00 |
23:39:26.25 |
-36:00:23.4 |
HIP 116614 |
19.20 |
| 2026-10-02 12:00 |
23:39:24.86 |
-36:00:26.7 |
HIP 116614 |
18.96 |
| 2026-10-03 00:00 |
23:39:23.48 |
-36:00:30.0 |
HIP 116614 |
18.73 |
| 2026-10-03 12:00 |
23:39:22.09 |
-36:00:33.2 |
HIP 116614 |
18.50 |
| 2026-10-04 00:00 |
23:39:20.71 |
-36:00:36.3 |
HIP 116614 |
18.27 |
| 2026-10-04 12:00 |
23:39:19.33 |
-36:00:39.3 |
HIP 116614 |
18.04 |
| 2026-10-05 00:00 |
23:39:17.96 |
-36:00:42.1 |
HIP 116614 |
17.81 |
| 2026-10-05 12:00 |
23:39:16.59 |
-36:00:44.9 |
HIP 116614 |
17.59 |
| 2026-10-06 00:00 |
23:39:15.22 |
-36:00:47.6 |
HIP 116614 |
17.36 |
| 2026-10-06 12:00 |
23:39:13.86 |
-36:00:50.1 |
HIP 116614 |
17.14 |
| 2026-10-07 00:00 |
23:39:12.50 |
-36:00:52.6 |
HIP 116614 |
16.92 |
| 2026-10-07 12:00 |
23:39:11.15 |
-36:00:54.9 |
HIP 116614 |
16.70 |
| 2026-10-08 00:00 |
23:39:09.80 |
-36:00:57.2 |
HIP 116614 |
16.48 |
| 2026-10-08 12:00 |
23:39:08.45 |
-36:00:59.3 |
HIP 116614 |
16.26 |
| 2026-10-09 00:00 |
23:39:07.11 |
-36:01:01.4 |
HIP 116614 |
16.04 |
| 2026-10-09 12:00 |
23:39:05.77 |
-36:01:03.3 |
HIP 116614 |
15.83 |
| 2026-10-10 00:00 |
23:39:04.44 |
-36:01:05.1 |
HIP 116614 |
15.62 |
| 2026-10-10 12:00 |
23:39:03.12 |
-36:01:06.8 |
HIP 116614 |
15.41 |
| 2026-10-11 00:00 |
23:39:01.79 |
-36:01:08.5 |
HIP 116614 |
15.20 |