C/1957 P1 (Mrkos)
Metadata
| Parameter | Value |
|---|---|
| Designation | C/1957 P1 (Mrkos) |
| Type | C |
| Perihelion (tp_cal, UTC) | 1957-08-01T10:26:12.068160Z |
| Orbit solution date (soln_date, UTC) | 2021-04-15T23:29:14Z |
| Obs used | 16 |
| NEO | - |
| M1 | - |
| K1 | - |
| PC | 0.030 |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 1958-03-10.0000000 |
| e | 0.99933801 |
| q (au) | 0.354936 |
| a (au) | 536.161864 |
| i (deg) | 93.956740 |
| Ω (om, deg) | 68.323840 |
| ω (w, deg) | 40.318515 |
| M (ma, deg) | 0.017510 |
Magnitude
Scatter + Global Linear
$$ M_a = (4.429 + 3.219\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 4.429 |
| n | 3.219 |
| gf | 0.800 |
| gb | -0.500 |
| k | 0.800 |
| δ90 | 1.000 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) | End (UTC) | a | b |
|---|---|---|---|
| 1957-08-02 | 1957-12-10 | -0.9783 | -0.115 |
| 1957-12-10 | 1958-07-09 | +21.2806 | -7.649 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) | RA (J2000) | Dec (J2000) | Nearest HIP | Dist from HIP (arcmin) |
|---|---|---|---|---|
| 2026-02-03 00:00 | 15:40:30.40 | -53:55:24.0 | HIP 77018 | 27.95 |
| 2026-02-03 12:00 | 15:40:30.91 | -53:55:35.8 | HIP 77018 | 27.82 |
| 2026-02-04 00:00 | 15:40:31.40 | -53:55:47.7 | HIP 77018 | 27.70 |
| 2026-02-04 12:00 | 15:40:31.87 | -53:55:59.5 | HIP 77018 | 27.58 |
| 2026-02-05 00:00 | 15:40:32.32 | -53:56:11.3 | HIP 77018 | 27.46 |
| 2026-02-05 12:00 | 15:40:32.76 | -53:56:23.1 | HIP 77018 | 27.35 |
| 2026-02-06 00:00 | 15:40:33.18 | -53:56:34.9 | HIP 77018 | 27.24 |
| 2026-02-06 12:00 | 15:40:33.58 | -53:56:46.7 | HIP 77018 | 27.13 |
| 2026-02-07 00:00 | 15:40:33.96 | -53:56:58.4 | HIP 77018 | 27.03 |
| 2026-02-07 12:00 | 15:40:34.32 | -53:57:10.2 | HIP 77018 | 26.93 |
| 2026-02-08 00:00 | 15:40:34.66 | -53:57:21.9 | HIP 77018 | 26.84 |
| 2026-02-08 12:00 | 15:40:34.99 | -53:57:33.7 | HIP 77018 | 26.75 |
| 2026-02-09 00:00 | 15:40:35.29 | -53:57:45.4 | HIP 77018 | 26.66 |
| 2026-02-09 12:00 | 15:40:35.58 | -53:57:57.1 | HIP 77018 | 26.58 |
| 2026-02-10 00:00 | 15:40:35.85 | -53:58:08.7 | HIP 77018 | 26.50 |
| 2026-02-10 12:00 | 15:40:36.10 | -53:58:20.4 | HIP 77018 | 26.43 |
| 2026-02-11 00:00 | 15:40:36.33 | -53:58:32.0 | HIP 77018 | 26.35 |
| 2026-02-11 12:00 | 15:40:36.54 | -53:58:43.6 | HIP 77018 | 26.29 |
| 2026-02-12 00:00 | 15:40:36.74 | -53:58:55.2 | HIP 77018 | 26.23 |
| 2026-02-12 12:00 | 15:40:36.91 | -53:59:06.8 | HIP 77018 | 26.17 |
| 2026-02-13 00:00 | 15:40:37.07 | -53:59:18.3 | HIP 77018 | 26.11 |
| 2026-02-13 12:00 | 15:40:37.20 | -53:59:29.9 | HIP 77018 | 26.06 |
| 2026-02-14 00:00 | 15:40:37.32 | -53:59:41.3 | HIP 77018 | 26.02 |
| 2026-02-14 12:00 | 15:40:37.42 | -53:59:52.8 | HIP 77018 | 25.98 |
| 2026-02-15 00:00 | 15:40:37.50 | -54:00:04.3 | HIP 77018 | 25.94 |
| 2026-02-15 12:00 | 15:40:37.56 | -54:00:15.7 | HIP 77018 | 25.91 |
| 2026-02-16 00:00 | 15:40:37.60 | -54:00:27.1 | HIP 77018 | 25.88 |
| 2026-02-16 12:00 | 15:40:37.63 | -54:00:38.4 | HIP 77018 | 25.85 |
| 2026-02-17 00:00 | 15:40:37.63 | -54:00:49.7 | HIP 77018 | 25.83 |
| 2026-02-17 12:00 | 15:40:37.61 | -54:01:01.0 | HIP 77018 | 25.82 |
| 2026-02-18 00:00 | 15:40:37.58 | -54:01:12.3 | HIP 77018 | 25.80 |
| 2026-02-18 12:00 | 15:40:37.53 | -54:01:23.5 | HIP 77018 | 25.80 |
| 2026-02-19 00:00 | 15:40:37.45 | -54:01:34.7 | HIP 77018 | 25.79 |
| 2026-02-19 12:00 | 15:40:37.36 | -54:01:45.8 | HIP 77018 | 25.79 |
| 2026-02-20 00:00 | 15:40:37.25 | -54:01:57.0 | HIP 77018 | 25.80 |
| 2026-02-20 12:00 | 15:40:37.12 | -54:02:08.1 | HIP 77018 | 25.81 |
| 2026-02-21 00:00 | 15:40:36.97 | -54:02:19.1 | HIP 77018 | 25.82 |
| 2026-02-21 12:00 | 15:40:36.81 | -54:02:30.1 | HIP 77018 | 25.84 |
| 2026-02-22 00:00 | 15:40:36.62 | -54:02:41.1 | HIP 77018 | 25.86 |
| 2026-02-22 12:00 | 15:40:36.41 | -54:02:52.0 | HIP 77018 | 25.88 |
| 2026-02-23 00:00 | 15:40:36.19 | -54:03:02.9 | HIP 77018 | 25.91 |
| 2026-02-23 12:00 | 15:40:35.95 | -54:03:13.7 | HIP 77018 | 25.94 |
| 2026-02-24 00:00 | 15:40:35.68 | -54:03:24.5 | HIP 77018 | 25.98 |