| 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 |
0.999 |
| gb |
-1.000 |
| k |
0.998 |
| δ90 |
9.998 |
| 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) |
| 2026-05-12 00:00 |
02:06:00.99 |
-04:13:15.3 |
HIP 9813 |
9.29 |
| 2026-05-12 12:00 |
02:06:02.05 |
-04:13:11.7 |
HIP 9813 |
9.26 |
| 2026-05-13 00:00 |
02:06:03.11 |
-04:13:08.1 |
HIP 9813 |
9.23 |
| 2026-05-13 12:00 |
02:06:04.16 |
-04:13:04.6 |
HIP 9813 |
9.20 |
| 2026-05-14 00:00 |
02:06:05.21 |
-04:13:01.1 |
HIP 9813 |
9.19 |
| 2026-05-14 12:00 |
02:06:06.25 |
-04:12:57.7 |
HIP 9813 |
9.18 |
| 2026-05-15 00:00 |
02:06:07.30 |
-04:12:54.4 |
HIP 9813 |
9.18 |
| 2026-05-15 12:00 |
02:06:08.34 |
-04:12:51.1 |
HIP 9813 |
9.19 |
| 2026-05-16 00:00 |
02:06:09.37 |
-04:12:47.8 |
HIP 9813 |
9.20 |
| 2026-05-16 12:00 |
02:06:10.40 |
-04:12:44.7 |
HIP 9813 |
9.22 |
| 2026-05-17 00:00 |
02:06:11.43 |
-04:12:41.5 |
HIP 9813 |
9.24 |
| 2026-05-17 12:00 |
02:06:12.46 |
-04:12:38.5 |
HIP 9813 |
9.27 |
| 2026-05-18 00:00 |
02:06:13.48 |
-04:12:35.5 |
HIP 9813 |
9.31 |
| 2026-05-18 12:00 |
02:06:14.50 |
-04:12:32.6 |
HIP 9813 |
9.36 |
| 2026-05-19 00:00 |
02:06:15.52 |
-04:12:29.7 |
HIP 9813 |
9.41 |
| 2026-05-19 12:00 |
02:06:16.53 |
-04:12:26.9 |
HIP 9813 |
9.46 |
| 2026-05-20 00:00 |
02:06:17.54 |
-04:12:24.1 |
HIP 9813 |
9.53 |
| 2026-05-20 12:00 |
02:06:18.54 |
-04:12:21.4 |
HIP 9813 |
9.59 |
| 2026-05-21 00:00 |
02:06:19.54 |
-04:12:18.8 |
HIP 9813 |
9.66 |
| 2026-05-21 12:00 |
02:06:20.53 |
-04:12:16.2 |
HIP 9813 |
9.74 |
| 2026-05-22 00:00 |
02:06:21.52 |
-04:12:13.7 |
HIP 9813 |
9.82 |
| 2026-05-22 12:00 |
02:06:22.51 |
-04:12:11.3 |
HIP 9874 |
9.86 |
| 2026-05-23 00:00 |
02:06:23.49 |
-04:12:08.9 |
HIP 9874 |
9.62 |
| 2026-05-23 12:00 |
02:06:24.47 |
-04:12:06.5 |
HIP 9874 |
9.38 |
| 2026-05-24 00:00 |
02:06:25.44 |
-04:12:04.3 |
HIP 9874 |
9.14 |
| 2026-05-24 12:00 |
02:06:26.41 |
-04:12:02.1 |
HIP 9874 |
8.91 |
| 2026-05-25 00:00 |
02:06:27.38 |
-04:12:00.0 |
HIP 9874 |
8.67 |
| 2026-05-25 12:00 |
02:06:28.34 |
-04:11:57.8 |
HIP 9874 |
8.44 |
| 2026-05-26 00:00 |
02:06:29.29 |
-04:11:55.8 |
HIP 9874 |
8.21 |
| 2026-05-26 12:00 |
02:06:30.24 |
-04:11:53.9 |
HIP 9874 |
7.98 |
| 2026-05-27 00:00 |
02:06:31.19 |
-04:11:52.0 |
HIP 9874 |
7.75 |
| 2026-05-27 12:00 |
02:06:32.13 |
-04:11:50.1 |
HIP 9874 |
7.52 |
| 2026-05-28 00:00 |
02:06:33.07 |
-04:11:48.4 |
HIP 9874 |
7.30 |
| 2026-05-28 12:00 |
02:06:34.00 |
-04:11:46.7 |
HIP 9874 |
7.07 |
| 2026-05-29 00:00 |
02:06:34.92 |
-04:11:45.0 |
HIP 9874 |
6.85 |
| 2026-05-29 12:00 |
02:06:35.84 |
-04:11:43.5 |
HIP 9874 |
6.63 |
| 2026-05-30 00:00 |
02:06:36.76 |
-04:11:41.9 |
HIP 9874 |
6.41 |
| 2026-05-30 12:00 |
02:06:37.67 |
-04:11:40.5 |
HIP 9874 |
6.20 |
| 2026-05-31 00:00 |
02:06:38.57 |
-04:11:39.1 |
HIP 9874 |
5.98 |
| 2026-05-31 12:00 |
02:06:39.47 |
-04:11:37.8 |
HIP 9874 |
5.77 |
| 2026-06-01 00:00 |
02:06:40.37 |
-04:11:36.5 |
HIP 9874 |
5.56 |
| 2026-06-01 12:00 |
02:06:41.25 |
-04:11:35.3 |
HIP 9874 |
5.35 |
| 2026-06-02 00:00 |
02:06:42.14 |
-04:11:34.2 |
HIP 9874 |
5.15 |