| 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) |
| 2026-09-20 00:00 |
02:06:38.82 |
-04:29:39.4 |
HIP 9813 |
9.82 |
| 2026-09-20 12:00 |
02:06:37.89 |
-04:29:47.7 |
HIP 9813 |
9.79 |
| 2026-09-21 00:00 |
02:06:36.95 |
-04:29:55.9 |
HIP 9813 |
9.77 |
| 2026-09-21 12:00 |
02:06:36.01 |
-04:30:04.2 |
HIP 9813 |
9.75 |
| 2026-09-22 00:00 |
02:06:35.06 |
-04:30:12.5 |
HIP 9813 |
9.74 |
| 2026-09-22 12:00 |
02:06:34.10 |
-04:30:20.7 |
HIP 9813 |
9.74 |
| 2026-09-23 00:00 |
02:06:33.14 |
-04:30:29.0 |
HIP 9813 |
9.74 |
| 2026-09-23 12:00 |
02:06:32.18 |
-04:30:37.2 |
HIP 9813 |
9.75 |
| 2026-09-24 00:00 |
02:06:31.20 |
-04:30:45.4 |
HIP 9813 |
9.77 |
| 2026-09-24 12:00 |
02:06:30.23 |
-04:30:53.6 |
HIP 9813 |
9.80 |
| 2026-09-25 00:00 |
02:06:29.24 |
-04:31:01.8 |
HIP 9813 |
9.83 |
| 2026-09-25 12:00 |
02:06:28.26 |
-04:31:10.0 |
HIP 9813 |
9.87 |
| 2026-09-26 00:00 |
02:06:27.26 |
-04:31:18.2 |
HIP 9813 |
9.91 |
| 2026-09-26 12:00 |
02:06:26.27 |
-04:31:26.3 |
HIP 9813 |
9.97 |
| 2026-09-27 00:00 |
02:06:25.26 |
-04:31:34.5 |
HIP 9813 |
10.03 |
| 2026-09-27 12:00 |
02:06:24.25 |
-04:31:42.6 |
HIP 9813 |
10.10 |
| 2026-09-28 00:00 |
02:06:23.24 |
-04:31:50.7 |
HIP 9813 |
10.17 |
| 2026-09-28 12:00 |
02:06:22.22 |
-04:31:58.8 |
HIP 9813 |
10.26 |
| 2026-09-29 00:00 |
02:06:21.20 |
-04:32:06.9 |
HIP 9813 |
10.34 |
| 2026-09-29 12:00 |
02:06:20.17 |
-04:32:15.0 |
HIP 9813 |
10.44 |
| 2026-09-30 00:00 |
02:06:19.14 |
-04:32:23.0 |
HIP 9813 |
10.54 |
| 2026-09-30 12:00 |
02:06:18.11 |
-04:32:31.1 |
HIP 9813 |
10.65 |
| 2026-10-01 00:00 |
02:06:17.07 |
-04:32:39.1 |
HIP 9813 |
10.77 |
| 2026-10-01 12:00 |
02:06:16.02 |
-04:32:47.1 |
HIP 9813 |
10.89 |
| 2026-10-02 00:00 |
02:06:14.97 |
-04:32:55.1 |
HIP 9813 |
11.02 |
| 2026-10-02 12:00 |
02:06:13.92 |
-04:33:03.0 |
HIP 9813 |
11.15 |
| 2026-10-03 00:00 |
02:06:12.86 |
-04:33:11.0 |
HIP 9813 |
11.29 |
| 2026-10-03 12:00 |
02:06:11.80 |
-04:33:18.9 |
HIP 9813 |
11.44 |
| 2026-10-04 00:00 |
02:06:10.73 |
-04:33:26.8 |
HIP 9813 |
11.59 |
| 2026-10-04 12:00 |
02:06:09.66 |
-04:33:34.6 |
HIP 9813 |
11.74 |
| 2026-10-05 00:00 |
02:06:08.59 |
-04:33:42.5 |
HIP 9813 |
11.90 |
| 2026-10-05 12:00 |
02:06:07.51 |
-04:33:50.3 |
HIP 9813 |
12.07 |
| 2026-10-06 00:00 |
02:06:06.43 |
-04:33:58.1 |
HIP 9813 |
12.24 |
| 2026-10-06 12:00 |
02:06:05.34 |
-04:34:05.9 |
HIP 9813 |
12.42 |
| 2026-10-07 00:00 |
02:06:04.25 |
-04:34:13.7 |
HIP 9813 |
12.60 |
| 2026-10-07 12:00 |
02:06:03.16 |
-04:34:21.4 |
HIP 9813 |
12.78 |
| 2026-10-08 00:00 |
02:06:02.06 |
-04:34:29.1 |
HIP 9813 |
12.97 |
| 2026-10-08 12:00 |
02:06:00.96 |
-04:34:36.8 |
HIP 9813 |
13.16 |
| 2026-10-09 00:00 |
02:05:59.86 |
-04:34:44.4 |
HIP 9813 |
13.36 |
| 2026-10-09 12:00 |
02:05:58.76 |
-04:34:52.0 |
HIP 9813 |
13.56 |
| 2026-10-10 00:00 |
02:05:57.65 |
-04:34:59.6 |
HIP 9813 |
13.76 |
| 2026-10-10 12:00 |
02:05:56.54 |
-04:35:07.2 |
HIP 9813 |
13.97 |
| 2026-10-11 00:00 |
02:05:55.42 |
-04:35:14.7 |
HIP 9813 |
14.18 |