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 | 1957-09-16 | -1.5729 | -0.263 |
| 1957-09-16 | 1958-07-09 | +11.5497 | -1.367 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) | RA (J2000) | Dec (J2000) | Nearest HIP | Dist from HIP (arcmin) |
|---|---|---|---|---|
| 2026-07-29 00:00 | 15:32:31.72 | -53:54:52.7 | HIP 75778 | 32.77 |
| 2026-07-29 12:00 | 15:32:31.02 | -53:54:41.3 | HIP 75778 | 32.67 |
| 2026-07-30 00:00 | 15:32:30.34 | -53:54:29.9 | HIP 75778 | 32.58 |
| 2026-07-30 12:00 | 15:32:29.67 | -53:54:18.5 | HIP 75778 | 32.49 |
| 2026-07-31 00:00 | 15:32:29.02 | -53:54:07.1 | HIP 75778 | 32.40 |
| 2026-07-31 12:00 | 15:32:28.38 | -53:53:55.7 | HIP 75778 | 32.32 |
| 2026-08-01 00:00 | 15:32:27.77 | -53:53:44.2 | HIP 75778 | 32.24 |
| 2026-08-01 12:00 | 15:32:27.17 | -53:53:32.8 | HIP 75778 | 32.16 |
| 2026-08-02 00:00 | 15:32:26.58 | -53:53:21.5 | HIP 75778 | 32.09 |
| 2026-08-02 12:00 | 15:32:26.02 | -53:53:10.1 | HIP 75778 | 32.02 |
| 2026-08-03 00:00 | 15:32:25.47 | -53:52:58.7 | HIP 75778 | 31.96 |
| 2026-08-03 12:00 | 15:32:24.94 | -53:52:47.3 | HIP 75778 | 31.90 |
| 2026-08-04 00:00 | 15:32:24.43 | -53:52:35.9 | HIP 75778 | 31.84 |
| 2026-08-04 12:00 | 15:32:23.93 | -53:52:24.6 | HIP 75778 | 31.79 |
| 2026-08-05 00:00 | 15:32:23.45 | -53:52:13.2 | HIP 75778 | 31.74 |
| 2026-08-05 12:00 | 15:32:22.99 | -53:52:01.9 | HIP 75778 | 31.69 |
| 2026-08-06 00:00 | 15:32:22.55 | -53:51:50.6 | HIP 75778 | 31.65 |
| 2026-08-06 12:00 | 15:32:22.12 | -53:51:39.3 | HIP 75778 | 31.61 |
| 2026-08-07 00:00 | 15:32:21.71 | -53:51:28.0 | HIP 75778 | 31.58 |
| 2026-08-07 12:00 | 15:32:21.32 | -53:51:16.7 | HIP 75778 | 31.55 |
| 2026-08-08 00:00 | 15:32:20.95 | -53:51:05.4 | HIP 75778 | 31.52 |
| 2026-08-08 12:00 | 15:32:20.60 | -53:50:54.2 | HIP 75778 | 31.50 |
| 2026-08-09 00:00 | 15:32:20.26 | -53:50:43.0 | HIP 75956 | 31.39 |
| 2026-08-09 12:00 | 15:32:19.94 | -53:50:31.8 | HIP 75956 | 31.20 |
| 2026-08-10 00:00 | 15:32:19.64 | -53:50:20.6 | HIP 75956 | 31.01 |
| 2026-08-10 12:00 | 15:32:19.35 | -53:50:09.4 | HIP 75956 | 30.83 |
| 2026-08-11 00:00 | 15:32:19.09 | -53:49:58.2 | HIP 75956 | 30.64 |
| 2026-08-11 12:00 | 15:32:18.84 | -53:49:47.1 | HIP 75956 | 30.46 |
| 2026-08-12 00:00 | 15:32:18.61 | -53:49:36.0 | HIP 75956 | 30.28 |
| 2026-08-12 12:00 | 15:32:18.40 | -53:49:24.9 | HIP 75956 | 30.10 |
| 2026-08-13 00:00 | 15:32:18.20 | -53:49:13.8 | HIP 75956 | 29.92 |
| 2026-08-13 12:00 | 15:32:18.03 | -53:49:02.8 | HIP 75956 | 29.75 |
| 2026-08-14 00:00 | 15:32:17.87 | -53:48:51.8 | HIP 75956 | 29.57 |
| 2026-08-14 12:00 | 15:32:17.73 | -53:48:40.8 | HIP 75956 | 29.40 |
| 2026-08-15 00:00 | 15:32:17.61 | -53:48:29.9 | HIP 75956 | 29.23 |
| 2026-08-15 12:00 | 15:32:17.50 | -53:48:18.9 | HIP 75956 | 29.06 |
| 2026-08-16 00:00 | 15:32:17.42 | -53:48:08.0 | HIP 75956 | 28.89 |
| 2026-08-16 12:00 | 15:32:17.35 | -53:47:57.2 | HIP 75956 | 28.73 |
| 2026-08-17 00:00 | 15:32:17.30 | -53:47:46.3 | HIP 75956 | 28.56 |
| 2026-08-17 12:00 | 15:32:17.26 | -53:47:35.5 | HIP 75956 | 28.40 |
| 2026-08-18 00:00 | 15:32:17.25 | -53:47:24.7 | HIP 75956 | 28.24 |
| 2026-08-18 12:00 | 15:32:17.25 | -53:47:14.0 | HIP 75956 | 28.08 |
| 2026-08-19 00:00 | 15:32:17.27 | -53:47:03.3 | HIP 75956 | 27.93 |