| Parameter |
Value |
| Designation |
C/1949 K1 (Johnson) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1950-01-19T07:03:40.668480Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:09Z |
| Obs used |
18 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1950-10-11.0000000 |
| e |
1.00071559 |
| q (au) |
2.553079 |
| a (au) |
-3567.814459 |
| i (deg) |
131.351658 |
| Ω (om, deg) |
222.334961 |
| ω (w, deg) |
40.088783 |
| M (ma, deg) |
0.001224 |
Magnitude
Scatter + Global Linear
$$
M_a = (3.685 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
3.685 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.998 |
| δ90 |
10.000 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
02:07:33.89 |
-04:16:20.3 |
HIP 9874 |
8.62 |
| 2026-07-29 12:00 |
02:07:33.83 |
-04:16:26.2 |
HIP 9874 |
8.65 |
| 2026-07-30 00:00 |
02:07:33.77 |
-04:16:32.1 |
HIP 9874 |
8.67 |
| 2026-07-30 12:00 |
02:07:33.70 |
-04:16:38.0 |
HIP 9874 |
8.70 |
| 2026-07-31 00:00 |
02:07:33.62 |
-04:16:44.0 |
HIP 9874 |
8.72 |
| 2026-07-31 12:00 |
02:07:33.53 |
-04:16:50.0 |
HIP 9874 |
8.75 |
| 2026-08-01 00:00 |
02:07:33.43 |
-04:16:56.1 |
HIP 9874 |
8.77 |
| 2026-08-01 12:00 |
02:07:33.32 |
-04:17:02.2 |
HIP 9874 |
8.79 |
| 2026-08-02 00:00 |
02:07:33.21 |
-04:17:08.4 |
HIP 9874 |
8.81 |
| 2026-08-02 12:00 |
02:07:33.08 |
-04:17:14.6 |
HIP 9874 |
8.83 |
| 2026-08-03 00:00 |
02:07:32.94 |
-04:17:20.9 |
HIP 9874 |
8.85 |
| 2026-08-03 12:00 |
02:07:32.80 |
-04:17:27.2 |
HIP 9874 |
8.87 |
| 2026-08-04 00:00 |
02:07:32.64 |
-04:17:33.5 |
HIP 9874 |
8.89 |
| 2026-08-04 12:00 |
02:07:32.48 |
-04:17:39.9 |
HIP 9874 |
8.91 |
| 2026-08-05 00:00 |
02:07:32.30 |
-04:17:46.3 |
HIP 9874 |
8.93 |
| 2026-08-05 12:00 |
02:07:32.12 |
-04:17:52.8 |
HIP 9874 |
8.95 |
| 2026-08-06 00:00 |
02:07:31.92 |
-04:17:59.3 |
HIP 9874 |
8.97 |
| 2026-08-06 12:00 |
02:07:31.72 |
-04:18:05.9 |
HIP 9874 |
8.98 |
| 2026-08-07 00:00 |
02:07:31.51 |
-04:18:12.5 |
HIP 9874 |
9.00 |
| 2026-08-07 12:00 |
02:07:31.29 |
-04:18:19.1 |
HIP 9874 |
9.02 |
| 2026-08-08 00:00 |
02:07:31.06 |
-04:18:25.8 |
HIP 9874 |
9.04 |
| 2026-08-08 12:00 |
02:07:30.82 |
-04:18:32.6 |
HIP 9874 |
9.06 |
| 2026-08-09 00:00 |
02:07:30.57 |
-04:18:39.3 |
HIP 9874 |
9.08 |
| 2026-08-09 12:00 |
02:07:30.31 |
-04:18:46.1 |
HIP 9874 |
9.10 |
| 2026-08-10 00:00 |
02:07:30.04 |
-04:18:53.0 |
HIP 9874 |
9.12 |
| 2026-08-10 12:00 |
02:07:29.76 |
-04:18:59.9 |
HIP 9874 |
9.14 |
| 2026-08-11 00:00 |
02:07:29.47 |
-04:19:06.8 |
HIP 9874 |
9.16 |
| 2026-08-11 12:00 |
02:07:29.18 |
-04:19:13.8 |
HIP 9874 |
9.19 |
| 2026-08-12 00:00 |
02:07:28.87 |
-04:19:20.8 |
HIP 9874 |
9.21 |
| 2026-08-12 12:00 |
02:07:28.55 |
-04:19:27.8 |
HIP 9874 |
9.23 |
| 2026-08-13 00:00 |
02:07:28.23 |
-04:19:34.9 |
HIP 9874 |
9.26 |
| 2026-08-13 12:00 |
02:07:27.90 |
-04:19:42.0 |
HIP 9874 |
9.28 |
| 2026-08-14 00:00 |
02:07:27.55 |
-04:19:49.1 |
HIP 9874 |
9.31 |
| 2026-08-14 12:00 |
02:07:27.20 |
-04:19:56.3 |
HIP 9874 |
9.34 |
| 2026-08-15 00:00 |
02:07:26.84 |
-04:20:03.5 |
HIP 9874 |
9.37 |
| 2026-08-15 12:00 |
02:07:26.47 |
-04:20:10.8 |
HIP 9874 |
9.40 |
| 2026-08-16 00:00 |
02:07:26.09 |
-04:20:18.1 |
HIP 9874 |
9.43 |
| 2026-08-16 12:00 |
02:07:25.70 |
-04:20:25.4 |
HIP 9874 |
9.46 |
| 2026-08-17 00:00 |
02:07:25.30 |
-04:20:32.7 |
HIP 9874 |
9.50 |
| 2026-08-17 12:00 |
02:07:24.89 |
-04:20:40.1 |
HIP 9874 |
9.53 |
| 2026-08-18 00:00 |
02:07:24.48 |
-04:20:47.5 |
HIP 9874 |
9.57 |
| 2026-08-18 12:00 |
02:07:24.05 |
-04:20:55.0 |
HIP 9874 |
9.61 |
| 2026-08-19 00:00 |
02:07:23.62 |
-04:21:02.4 |
HIP 9874 |
9.65 |