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) |
|---|---|---|---|---|
| 2026-09-20 00:00 | 15:32:54.65 | -53:37:21.3 | HIP 75956 | 23.99 |
| 2026-09-20 12:00 | 15:32:55.76 | -53:37:14.3 | HIP 75956 | 24.05 |
| 2026-09-21 00:00 | 15:32:56.89 | -53:37:07.3 | HIP 75956 | 24.11 |
| 2026-09-21 12:00 | 15:32:58.04 | -53:37:00.5 | HIP 75956 | 24.18 |
| 2026-09-22 00:00 | 15:32:59.20 | -53:36:53.7 | HIP 75956 | 24.25 |
| 2026-09-22 12:00 | 15:33:00.38 | -53:36:47.0 | HIP 75956 | 24.33 |
| 2026-09-23 00:00 | 15:33:01.57 | -53:36:40.4 | HIP 75956 | 24.41 |
| 2026-09-23 12:00 | 15:33:02.77 | -53:36:33.8 | HIP 75956 | 24.49 |
| 2026-09-24 00:00 | 15:33:03.99 | -53:36:27.4 | HIP 75956 | 24.58 |
| 2026-09-24 12:00 | 15:33:05.23 | -53:36:21.0 | HIP 75956 | 24.67 |
| 2026-09-25 00:00 | 15:33:06.48 | -53:36:14.7 | HIP 75956 | 24.76 |
| 2026-09-25 12:00 | 15:33:07.74 | -53:36:08.5 | HIP 75956 | 24.86 |
| 2026-09-26 00:00 | 15:33:09.02 | -53:36:02.3 | HIP 75956 | 24.97 |
| 2026-09-26 12:00 | 15:33:10.31 | -53:35:56.3 | HIP 75956 | 25.07 |
| 2026-09-27 00:00 | 15:33:11.61 | -53:35:50.3 | HIP 75956 | 25.19 |
| 2026-09-27 12:00 | 15:33:12.93 | -53:35:44.4 | HIP 75956 | 25.30 |
| 2026-09-28 00:00 | 15:33:14.26 | -53:35:38.6 | HIP 75956 | 25.42 |
| 2026-09-28 12:00 | 15:33:15.61 | -53:35:32.9 | HIP 75956 | 25.54 |
| 2026-09-29 00:00 | 15:33:16.97 | -53:35:27.3 | HIP 75956 | 25.67 |
| 2026-09-29 12:00 | 15:33:18.34 | -53:35:21.7 | HIP 75956 | 25.80 |
| 2026-09-30 00:00 | 15:33:19.72 | -53:35:16.2 | HIP 75956 | 25.93 |
| 2026-09-30 12:00 | 15:33:21.12 | -53:35:10.8 | HIP 75956 | 26.07 |
| 2026-10-01 00:00 | 15:33:22.54 | -53:35:05.5 | HIP 75956 | 26.21 |
| 2026-10-01 12:00 | 15:33:23.96 | -53:35:00.3 | HIP 75956 | 26.36 |
| 2026-10-02 00:00 | 15:33:25.40 | -53:34:55.2 | HIP 75956 | 26.51 |
| 2026-10-02 12:00 | 15:33:26.85 | -53:34:50.2 | HIP 75956 | 26.66 |
| 2026-10-03 00:00 | 15:33:28.32 | -53:34:45.2 | HIP 76411 | 26.69 |
| 2026-10-03 12:00 | 15:33:29.80 | -53:34:40.3 | HIP 76411 | 26.46 |
| 2026-10-04 00:00 | 15:33:31.29 | -53:34:35.5 | HIP 76411 | 26.23 |
| 2026-10-04 12:00 | 15:33:32.79 | -53:34:30.9 | HIP 76411 | 25.99 |
| 2026-10-05 00:00 | 15:33:34.30 | -53:34:26.2 | HIP 76411 | 25.76 |
| 2026-10-05 12:00 | 15:33:35.83 | -53:34:21.7 | HIP 76411 | 25.52 |
| 2026-10-06 00:00 | 15:33:37.37 | -53:34:17.3 | HIP 76411 | 25.28 |
| 2026-10-06 12:00 | 15:33:38.92 | -53:34:13.0 | HIP 76411 | 25.04 |
| 2026-10-07 00:00 | 15:33:40.49 | -53:34:08.7 | HIP 76411 | 24.80 |
| 2026-10-07 12:00 | 15:33:42.06 | -53:34:04.6 | HIP 76411 | 24.56 |
| 2026-10-08 00:00 | 15:33:43.65 | -53:34:00.5 | HIP 76411 | 24.31 |
| 2026-10-08 12:00 | 15:33:45.25 | -53:33:56.5 | HIP 76411 | 24.07 |
| 2026-10-09 00:00 | 15:33:46.86 | -53:33:52.7 | HIP 76411 | 23.82 |
| 2026-10-09 12:00 | 15:33:48.49 | -53:33:48.9 | HIP 76411 | 23.57 |
| 2026-10-10 00:00 | 15:33:50.12 | -53:33:45.2 | HIP 76411 | 23.32 |
| 2026-10-10 12:00 | 15:33:51.77 | -53:33:41.6 | HIP 76411 | 23.07 |
| 2026-10-11 00:00 | 15:33:53.42 | -53:33:38.1 | HIP 76411 | 22.82 |