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 | 5.474 |
| 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) |
|---|---|---|---|---|
| 2026-06-01 00:00 | 10:08:40.00 | +50:28:50.2 | HIP 49727 | 20.93 |
| 2026-06-01 12:00 | 10:08:40.59 | +50:27:17.9 | HIP 49727 | 22.41 |
| 2026-06-02 00:00 | 10:08:41.27 | +50:25:45.5 | HIP 49727 | 23.91 |
| 2026-06-02 12:00 | 10:08:42.04 | +50:24:13.1 | HIP 49727 | 25.40 |
| 2026-06-03 00:00 | 10:08:42.90 | +50:22:40.7 | HIP 49727 | 26.90 |
| 2026-06-03 12:00 | 10:08:43.84 | +50:21:08.2 | HIP 49727 | 28.41 |
| 2026-06-04 00:00 | 10:08:44.88 | +50:19:35.8 | HIP 49727 | 29.91 |
| 2026-06-04 12:00 | 10:08:46.00 | +50:18:03.3 | HIP 49727 | 31.42 |
| 2026-06-05 00:00 | 10:08:47.21 | +50:16:30.8 | HIP 49727 | 32.94 |
| 2026-06-05 12:00 | 10:08:48.50 | +50:14:58.3 | HIP 49727 | 34.45 |
| 2026-06-06 00:00 | 10:08:49.89 | +50:13:25.7 | HIP 49727 | 35.97 |
| 2026-06-06 12:00 | 10:08:51.35 | +50:11:53.2 | HIP 49727 | 37.49 |
| 2026-06-07 00:00 | 10:08:52.91 | +50:10:20.7 | HIP 49727 | 39.01 |
| 2026-06-07 12:00 | 10:08:54.55 | +50:08:48.2 | HIP 49727 | 40.53 |
| 2026-06-08 00:00 | 10:08:56.27 | +50:07:15.7 | HIP 49825 | 39.05 |
| 2026-06-08 12:00 | 10:08:58.08 | +50:05:43.2 | HIP 49825 | 37.50 |
| 2026-06-09 00:00 | 10:08:59.97 | +50:04:10.7 | HIP 49825 | 35.95 |
| 2026-06-09 12:00 | 10:09:01.95 | +50:02:38.3 | HIP 49825 | 34.39 |
| 2026-06-10 00:00 | 10:09:04.01 | +50:01:05.9 | HIP 49825 | 32.84 |
| 2026-06-10 12:00 | 10:09:06.15 | +49:59:33.5 | HIP 49825 | 31.28 |
| 2026-06-11 00:00 | 10:09:08.37 | +49:58:01.2 | HIP 49825 | 29.72 |
| 2026-06-11 12:00 | 10:09:10.68 | +49:56:28.9 | HIP 49825 | 28.15 |
| 2026-06-12 00:00 | 10:09:13.06 | +49:54:56.7 | HIP 49825 | 26.59 |
| 2026-06-12 12:00 | 10:09:15.53 | +49:53:24.5 | HIP 49825 | 25.02 |
| 2026-06-13 00:00 | 10:09:18.07 | +49:51:52.3 | HIP 49825 | 23.45 |
| 2026-06-13 12:00 | 10:09:20.70 | +49:50:20.3 | HIP 49825 | 21.88 |
| 2026-06-14 00:00 | 10:09:23.40 | +49:48:48.3 | HIP 49825 | 20.30 |
| 2026-06-14 12:00 | 10:09:26.19 | +49:47:16.3 | HIP 49825 | 18.73 |
| 2026-06-15 00:00 | 10:09:29.05 | +49:45:44.5 | HIP 49825 | 17.15 |
| 2026-06-15 12:00 | 10:09:31.99 | +49:44:12.7 | HIP 49825 | 15.57 |
| 2026-06-16 00:00 | 10:09:35.01 | +49:42:41.0 | HIP 49825 | 14.00 |
| 2026-06-16 12:00 | 10:09:38.10 | +49:41:09.4 | HIP 49825 | 12.42 |
| 2026-06-17 00:00 | 10:09:41.27 | +49:39:37.9 | HIP 49825 | 10.85 |
| 2026-06-17 12:00 | 10:09:44.51 | +49:38:06.5 | HIP 49825 | 9.29 |
| 2026-06-18 00:00 | 10:09:47.83 | +49:36:35.2 | HIP 49825 | 7.75 |
| 2026-06-18 12:00 | 10:09:51.22 | +49:35:04.0 | HIP 49825 | 6.23 |
| 2026-06-19 00:00 | 10:09:54.69 | +49:33:32.9 | HIP 49825 | 4.76 |
| 2026-06-19 12:00 | 10:09:58.23 | +49:32:01.9 | HIP 49825 | 3.43 |
| 2026-06-20 00:00 | 10:10:01.84 | +49:30:31.1 | HIP 49825 | 2.45 |
| 2026-06-20 12:00 | 10:10:05.52 | +49:29:00.4 | HIP 49825 | 2.35 |
| 2026-06-21 00:00 | 10:10:09.27 | +49:27:29.8 | HIP 49825 | 3.20 |
| 2026-06-21 12:00 | 10:10:13.10 | +49:25:59.3 | HIP 49825 | 4.50 |
| 2026-06-22 00:00 | 10:10:16.99 | +49:24:29.0 | HIP 49825 | 5.96 |