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) |
|---|---|---|---|---|
| 2026-03-26 00:00 | 15:39:47.02 | -54:12:26.4 | HIP 76497 | 22.63 |
| 2026-03-26 12:00 | 15:39:45.69 | -54:12:33.2 | HIP 76497 | 22.41 |
| 2026-03-27 00:00 | 15:39:44.36 | -54:12:40.0 | HIP 76497 | 22.18 |
| 2026-03-27 12:00 | 15:39:43.00 | -54:12:46.6 | HIP 76497 | 21.96 |
| 2026-03-28 00:00 | 15:39:41.64 | -54:12:53.2 | HIP 76497 | 21.73 |
| 2026-03-28 12:00 | 15:39:40.26 | -54:12:59.7 | HIP 76497 | 21.50 |
| 2026-03-29 00:00 | 15:39:38.86 | -54:13:06.1 | HIP 76497 | 21.27 |
| 2026-03-29 12:00 | 15:39:37.45 | -54:13:12.4 | HIP 76497 | 21.04 |
| 2026-03-30 00:00 | 15:39:36.03 | -54:13:18.6 | HIP 76497 | 20.81 |
| 2026-03-30 12:00 | 15:39:34.59 | -54:13:24.7 | HIP 76497 | 20.57 |
| 2026-03-31 00:00 | 15:39:33.13 | -54:13:30.8 | HIP 76497 | 20.34 |
| 2026-03-31 12:00 | 15:39:31.67 | -54:13:36.7 | HIP 76497 | 20.10 |
| 2026-04-01 00:00 | 15:39:30.19 | -54:13:42.6 | HIP 76497 | 19.86 |
| 2026-04-01 12:00 | 15:39:28.69 | -54:13:48.4 | HIP 76497 | 19.63 |
| 2026-04-02 00:00 | 15:39:27.19 | -54:13:54.1 | HIP 76497 | 19.39 |
| 2026-04-02 12:00 | 15:39:25.66 | -54:13:59.7 | HIP 76497 | 19.14 |
| 2026-04-03 00:00 | 15:39:24.13 | -54:14:05.2 | HIP 76497 | 18.90 |
| 2026-04-03 12:00 | 15:39:22.58 | -54:14:10.6 | HIP 76497 | 18.66 |
| 2026-04-04 00:00 | 15:39:21.02 | -54:14:15.9 | HIP 76497 | 18.42 |
| 2026-04-04 12:00 | 15:39:19.45 | -54:14:21.2 | HIP 76497 | 18.17 |
| 2026-04-05 00:00 | 15:39:17.86 | -54:14:26.3 | HIP 76497 | 17.92 |
| 2026-04-05 12:00 | 15:39:16.26 | -54:14:31.4 | HIP 76497 | 17.68 |
| 2026-04-06 00:00 | 15:39:14.65 | -54:14:36.3 | HIP 76497 | 17.43 |
| 2026-04-06 12:00 | 15:39:13.02 | -54:14:41.2 | HIP 76497 | 17.18 |
| 2026-04-07 00:00 | 15:39:11.39 | -54:14:46.0 | HIP 76497 | 16.93 |
| 2026-04-07 12:00 | 15:39:09.74 | -54:14:50.6 | HIP 76497 | 16.68 |
| 2026-04-08 00:00 | 15:39:08.07 | -54:14:55.2 | HIP 76497 | 16.42 |
| 2026-04-08 12:00 | 15:39:06.40 | -54:14:59.7 | HIP 76497 | 16.17 |
| 2026-04-09 00:00 | 15:39:04.71 | -54:15:04.1 | HIP 76497 | 15.92 |
| 2026-04-09 12:00 | 15:39:03.02 | -54:15:08.4 | HIP 76497 | 15.66 |
| 2026-04-10 00:00 | 15:39:01.31 | -54:15:12.6 | HIP 76497 | 15.41 |
| 2026-04-10 12:00 | 15:38:59.58 | -54:15:16.7 | HIP 76497 | 15.15 |
| 2026-04-11 00:00 | 15:38:57.85 | -54:15:20.7 | HIP 76497 | 14.89 |
| 2026-04-11 12:00 | 15:38:56.11 | -54:15:24.6 | HIP 76497 | 14.64 |
| 2026-04-12 00:00 | 15:38:54.35 | -54:15:28.4 | HIP 76497 | 14.38 |
| 2026-04-12 12:00 | 15:38:52.59 | -54:15:32.1 | HIP 76497 | 14.12 |
| 2026-04-13 00:00 | 15:38:50.81 | -54:15:35.7 | HIP 76497 | 13.86 |
| 2026-04-13 12:00 | 15:38:49.02 | -54:15:39.3 | HIP 76497 | 13.60 |
| 2026-04-14 00:00 | 15:38:47.22 | -54:15:42.7 | HIP 76497 | 13.34 |
| 2026-04-14 12:00 | 15:38:45.41 | -54:15:46.0 | HIP 76497 | 13.08 |
| 2026-04-15 00:00 | 15:38:43.59 | -54:15:49.2 | HIP 76497 | 12.82 |
| 2026-04-15 12:00 | 15:38:41.76 | -54:15:52.3 | HIP 76497 | 12.56 |
| 2026-04-16 00:00 | 15:38:39.92 | -54:15:55.4 | HIP 76497 | 12.31 |