C/2019 K7 (Smith)
Metadata
| Parameter | Value |
|---|---|
| Designation | C/2019 K7 (Smith) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2020-06-16T23:22:59.520000Z |
| Orbit solution date (soln_date, UTC) | 2024-07-30T14:57:24Z |
| Obs used | 2719 |
| NEO | - |
| M1 | 10.100 |
| K1 | 4.500 |
| PC | - |
| Discovery observation (MPC, UTC) | 2019-05-30T13:34:05.376000Z |
| Discovery magnitude (MPC) | 17.70 c |
| Discovery observatory (MPC) | T05 · ATLAS-HKO, Haleakala |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2021-01-12.0000000 |
| e | 0.99998658 |
| q (au) | 4.475189 |
| a (au) | 333367.353622 |
| i (deg) | 103.541946 |
| Ω (om, deg) | 307.929065 |
| ω (w, deg) | 27.308050 |
| M (ma, deg) | 0.000001 |
Magnitude
Scatter + Global Linear
$$ M_a = (10.047 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 10.047 |
| n | 2.000 |
| gf | 0.906 |
| gb | -0.650 |
| k | 0.965 |
| δ90 | 5.472 |
| 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 |
|---|---|---|---|
| 2017-10-08 | 2020-06-15 | +3.9313 | -2.529 |
| 2020-06-17 | 2021-04-08 | -4.3932 | +2.795 |
| 2021-04-08 | 2024-04-04 | +0.2227 | -0.255 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Finding Chart
Ephemeris
| Date/Time (UTC) | RA (J2000) | Dec (J2000) | Nearest HIP | Dist from HIP (arcmin) |
|---|---|---|---|---|
| 2026-03-26 00:00 | 10:22:37.50 | +53:10:14.8 | HIP 50917 | 13.62 |
| 2026-03-26 12:00 | 10:22:24.72 | +53:09:40.1 | HIP 50917 | 14.92 |
| 2026-03-27 00:00 | 10:22:12.02 | +53:09:04.5 | HIP 50917 | 16.35 |
| 2026-03-27 12:00 | 10:21:59.40 | +53:08:28.2 | HIP 50917 | 17.88 |
| 2026-03-28 00:00 | 10:21:46.86 | +53:07:51.0 | HIP 50625 | 18.72 |
| 2026-03-28 12:00 | 10:21:34.40 | +53:07:13.0 | HIP 50625 | 17.06 |
| 2026-03-29 00:00 | 10:21:22.02 | +53:06:34.3 | HIP 50625 | 15.48 |
| 2026-03-29 12:00 | 10:21:09.72 | +53:05:54.7 | HIP 50625 | 13.99 |
| 2026-03-30 00:00 | 10:20:57.51 | +53:05:14.4 | HIP 50625 | 12.62 |
| 2026-03-30 12:00 | 10:20:45.38 | +53:04:33.3 | HIP 50625 | 11.42 |
| 2026-03-31 00:00 | 10:20:33.33 | +53:03:51.4 | HIP 50625 | 10.42 |
| 2026-03-31 12:00 | 10:20:21.37 | +53:03:08.8 | HIP 50625 | 9.71 |
| 2026-04-01 00:00 | 10:20:09.50 | +53:02:25.3 | HIP 50625 | 9.33 |
| 2026-04-01 12:00 | 10:19:57.71 | +53:01:41.2 | HIP 50625 | 9.33 |
| 2026-04-02 00:00 | 10:19:46.01 | +53:00:56.3 | HIP 50625 | 9.70 |
| 2026-04-02 12:00 | 10:19:34.40 | +53:00:10.6 | HIP 50625 | 10.40 |
| 2026-04-03 00:00 | 10:19:22.88 | +52:59:24.2 | HIP 50625 | 11.36 |
| 2026-04-03 12:00 | 10:19:11.44 | +52:58:37.0 | HIP 50625 | 12.51 |
| 2026-04-04 00:00 | 10:19:00.10 | +52:57:49.1 | HIP 50625 | 13.82 |
| 2026-04-04 12:00 | 10:18:48.84 | +52:57:00.5 | HIP 50625 | 15.23 |
| 2026-04-05 00:00 | 10:18:37.68 | +52:56:11.2 | HIP 50625 | 16.73 |
| 2026-04-05 12:00 | 10:18:26.61 | +52:55:21.2 | HIP 50625 | 18.27 |
| 2026-04-06 00:00 | 10:18:15.64 | +52:54:30.4 | HIP 50625 | 19.86 |
| 2026-04-06 12:00 | 10:18:04.75 | +52:53:38.9 | HIP 50625 | 21.48 |
| 2026-04-07 00:00 | 10:17:53.96 | +52:52:46.8 | HIP 50625 | 23.12 |
| 2026-04-07 12:00 | 10:17:43.27 | +52:51:53.9 | HIP 50625 | 24.78 |
| 2026-04-08 00:00 | 10:17:32.67 | +52:51:00.4 | HIP 50184 | 26.28 |
| 2026-04-08 12:00 | 10:17:22.16 | +52:50:06.1 | HIP 50184 | 24.79 |
| 2026-04-09 00:00 | 10:17:11.75 | +52:49:11.2 | HIP 50184 | 23.37 |
| 2026-04-09 12:00 | 10:17:01.44 | +52:48:15.6 | HIP 50184 | 22.02 |
| 2026-04-10 00:00 | 10:16:51.23 | +52:47:19.4 | HIP 50184 | 20.76 |
| 2026-04-10 12:00 | 10:16:41.12 | +52:46:22.5 | HIP 50184 | 19.61 |
| 2026-04-11 00:00 | 10:16:31.10 | +52:45:24.9 | HIP 50184 | 18.57 |
| 2026-04-11 12:00 | 10:16:21.18 | +52:44:26.6 | HIP 50184 | 17.67 |
| 2026-04-12 00:00 | 10:16:11.36 | +52:43:27.8 | HIP 50184 | 16.93 |
| 2026-04-12 12:00 | 10:16:01.64 | +52:42:28.3 | HIP 50184 | 16.37 |
| 2026-04-13 00:00 | 10:15:52.03 | +52:41:28.1 | HIP 50184 | 16.00 |
| 2026-04-13 12:00 | 10:15:42.51 | +52:40:27.3 | HIP 50184 | 15.84 |
| 2026-04-14 00:00 | 10:15:33.10 | +52:39:25.9 | HIP 50184 | 15.89 |
| 2026-04-14 12:00 | 10:15:23.78 | +52:38:23.9 | HIP 50125 | 15.32 |
| 2026-04-15 00:00 | 10:15:14.57 | +52:37:21.2 | HIP 50125 | 13.59 |
| 2026-04-15 12:00 | 10:15:05.47 | +52:36:18.0 | HIP 50125 | 11.87 |
| 2026-04-16 00:00 | 10:14:56.46 | +52:35:14.2 | HIP 50125 | 10.16 |