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) |
|---|---|---|---|---|
| 2026-05-12 00:00 | 15:36:54.17 | -54:16:12.6 | HIP 76497 | 7.33 |
| 2026-05-12 12:00 | 15:36:52.02 | -54:16:10.3 | HIP 76497 | 7.56 |
| 2026-05-13 00:00 | 15:36:49.87 | -54:16:07.8 | HIP 76497 | 7.80 |
| 2026-05-13 12:00 | 15:36:47.71 | -54:16:05.3 | HIP 76497 | 8.04 |
| 2026-05-14 00:00 | 15:36:45.55 | -54:16:02.6 | HIP 76497 | 8.30 |
| 2026-05-14 12:00 | 15:36:43.39 | -54:15:59.9 | HIP 76497 | 8.56 |
| 2026-05-15 00:00 | 15:36:41.23 | -54:15:57.0 | HIP 76497 | 8.82 |
| 2026-05-15 12:00 | 15:36:39.07 | -54:15:54.1 | HIP 76497 | 9.09 |
| 2026-05-16 00:00 | 15:36:36.91 | -54:15:51.0 | HIP 76497 | 9.36 |
| 2026-05-16 12:00 | 15:36:34.75 | -54:15:47.9 | HIP 76497 | 9.64 |
| 2026-05-17 00:00 | 15:36:32.59 | -54:15:44.7 | HIP 76497 | 9.92 |
| 2026-05-17 12:00 | 15:36:30.42 | -54:15:41.3 | HIP 76497 | 10.20 |
| 2026-05-18 00:00 | 15:36:28.26 | -54:15:37.9 | HIP 76497 | 10.49 |
| 2026-05-18 12:00 | 15:36:26.10 | -54:15:34.3 | HIP 76497 | 10.78 |
| 2026-05-19 00:00 | 15:36:23.94 | -54:15:30.7 | HIP 76497 | 11.07 |
| 2026-05-19 12:00 | 15:36:21.78 | -54:15:27.0 | HIP 76497 | 11.36 |
| 2026-05-20 00:00 | 15:36:19.62 | -54:15:23.2 | HIP 76497 | 11.66 |
| 2026-05-20 12:00 | 15:36:17.46 | -54:15:19.2 | HIP 76497 | 11.96 |
| 2026-05-21 00:00 | 15:36:15.30 | -54:15:15.2 | HIP 76497 | 12.26 |
| 2026-05-21 12:00 | 15:36:13.14 | -54:15:11.1 | HIP 76497 | 12.56 |
| 2026-05-22 00:00 | 15:36:10.99 | -54:15:06.9 | HIP 76497 | 12.87 |
| 2026-05-22 12:00 | 15:36:08.83 | -54:15:02.6 | HIP 76497 | 13.17 |
| 2026-05-23 00:00 | 15:36:06.68 | -54:14:58.2 | HIP 76497 | 13.48 |
| 2026-05-23 12:00 | 15:36:04.53 | -54:14:53.7 | HIP 76497 | 13.79 |
| 2026-05-24 00:00 | 15:36:02.38 | -54:14:49.1 | HIP 76497 | 14.10 |
| 2026-05-24 12:00 | 15:36:00.24 | -54:14:44.5 | HIP 76497 | 14.41 |
| 2026-05-25 00:00 | 15:35:58.09 | -54:14:39.7 | HIP 76497 | 14.72 |
| 2026-05-25 12:00 | 15:35:55.95 | -54:14:34.9 | HIP 76497 | 15.03 |
| 2026-05-26 00:00 | 15:35:53.81 | -54:14:29.9 | HIP 76497 | 15.34 |
| 2026-05-26 12:00 | 15:35:51.68 | -54:14:24.9 | HIP 76497 | 15.66 |
| 2026-05-27 00:00 | 15:35:49.55 | -54:14:19.8 | HIP 76497 | 15.97 |
| 2026-05-27 12:00 | 15:35:47.42 | -54:14:14.5 | HIP 76497 | 16.29 |
| 2026-05-28 00:00 | 15:35:45.29 | -54:14:09.2 | HIP 76497 | 16.60 |
| 2026-05-28 12:00 | 15:35:43.17 | -54:14:03.8 | HIP 76497 | 16.92 |
| 2026-05-29 00:00 | 15:35:41.05 | -54:13:58.4 | HIP 76497 | 17.24 |
| 2026-05-29 12:00 | 15:35:38.93 | -54:13:52.8 | HIP 76497 | 17.55 |
| 2026-05-30 00:00 | 15:35:36.82 | -54:13:47.1 | HIP 76497 | 17.87 |
| 2026-05-30 12:00 | 15:35:34.72 | -54:13:41.4 | HIP 76497 | 18.19 |
| 2026-05-31 00:00 | 15:35:32.61 | -54:13:35.6 | HIP 76497 | 18.51 |
| 2026-05-31 12:00 | 15:35:30.51 | -54:13:29.6 | HIP 76497 | 18.82 |
| 2026-06-01 00:00 | 15:35:28.42 | -54:13:23.6 | HIP 76497 | 19.14 |
| 2026-06-01 12:00 | 15:35:26.33 | -54:13:17.5 | HIP 76497 | 19.46 |
| 2026-06-02 00:00 | 15:35:24.24 | -54:13:11.4 | HIP 76497 | 19.78 |