C/1999 K1 (SOHO)
| Parameter |
Value |
| Designation |
C/1999 K1 (SOHO) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1999-05-21T08:52:48Z |
| Orbit solution date (soln_date, UTC) |
- |
| Obs used |
40 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1999-05-21.3700000 |
| e |
1.00000000 |
| q (au) |
0.005100 |
| a (au) |
- |
| i (deg) |
143.780000 |
| Ω (om, deg) |
5.490000 |
| ω (w, deg) |
83.510000 |
| M (ma, deg) |
- |
Magnitude
Scatter + Global Linear
$$
M_a = (H_0 + n\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
- |
| n |
- |
| gf |
- |
| gb |
- |
| k |
- |
| δ90 |
- |
| 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) |
| 2026-02-03 00:00 |
06:46:58.56 |
-13:33:59.4 |
HIP 32589 |
16.57 |
| 2026-02-03 12:00 |
06:46:56.50 |
-13:33:45.8 |
HIP 32589 |
17.12 |
| 2026-02-04 00:00 |
06:46:54.46 |
-13:33:32.1 |
HIP 32589 |
17.66 |
| 2026-02-04 12:00 |
06:46:52.42 |
-13:33:18.3 |
HIP 32589 |
18.21 |
| 2026-02-05 00:00 |
06:46:50.40 |
-13:33:04.3 |
HIP 32589 |
18.75 |
| 2026-02-05 12:00 |
06:46:48.39 |
-13:32:50.2 |
HIP 32589 |
19.29 |
| 2026-02-06 00:00 |
06:46:46.40 |
-13:32:35.9 |
HIP 32589 |
19.83 |
| 2026-02-06 12:00 |
06:46:44.42 |
-13:32:21.5 |
HIP 32589 |
20.37 |
| 2026-02-07 00:00 |
06:46:42.45 |
-13:32:07.0 |
HIP 32420 |
20.45 |
| 2026-02-07 12:00 |
06:46:40.49 |
-13:31:52.3 |
HIP 32420 |
20.46 |
| 2026-02-08 00:00 |
06:46:38.55 |
-13:31:37.5 |
HIP 32420 |
20.48 |
| 2026-02-08 12:00 |
06:46:36.62 |
-13:31:22.5 |
HIP 32420 |
20.52 |
| 2026-02-09 00:00 |
06:46:34.71 |
-13:31:07.5 |
HIP 32420 |
20.58 |
| 2026-02-09 12:00 |
06:46:32.80 |
-13:30:52.3 |
HIP 32420 |
20.65 |
| 2026-02-10 00:00 |
06:46:30.92 |
-13:30:37.0 |
HIP 32420 |
20.74 |
| 2026-02-10 12:00 |
06:46:29.04 |
-13:30:21.5 |
HIP 32420 |
20.85 |
| 2026-02-11 00:00 |
06:46:27.19 |
-13:30:05.9 |
HIP 32420 |
20.97 |
| 2026-02-11 12:00 |
06:46:25.34 |
-13:29:50.2 |
HIP 32420 |
21.11 |
| 2026-02-12 00:00 |
06:46:23.51 |
-13:29:34.4 |
HIP 32420 |
21.26 |
| 2026-02-12 12:00 |
06:46:21.70 |
-13:29:18.5 |
HIP 32420 |
21.43 |
| 2026-02-13 00:00 |
06:46:19.90 |
-13:29:02.4 |
HIP 32420 |
21.61 |
| 2026-02-13 12:00 |
06:46:18.11 |
-13:28:46.2 |
HIP 32420 |
21.80 |
| 2026-02-14 00:00 |
06:46:16.34 |
-13:28:29.9 |
HIP 32420 |
22.00 |
| 2026-02-14 12:00 |
06:46:14.59 |
-13:28:13.5 |
HIP 32420 |
22.22 |
| 2026-02-15 00:00 |
06:46:12.85 |
-13:27:57.0 |
HIP 32347 |
22.24 |
| 2026-02-15 12:00 |
06:46:11.13 |
-13:27:40.3 |
HIP 32347 |
21.75 |
| 2026-02-16 00:00 |
06:46:09.42 |
-13:27:23.6 |
HIP 32347 |
21.26 |
| 2026-02-16 12:00 |
06:46:07.73 |
-13:27:06.7 |
HIP 32347 |
20.77 |
| 2026-02-17 00:00 |
06:46:06.05 |
-13:26:49.7 |
HIP 32347 |
20.28 |
| 2026-02-17 12:00 |
06:46:04.39 |
-13:26:32.6 |
HIP 32347 |
19.79 |
| 2026-02-18 00:00 |
06:46:02.75 |
-13:26:15.4 |
HIP 32347 |
19.31 |
| 2026-02-18 12:00 |
06:46:01.12 |
-13:25:58.2 |
HIP 32347 |
18.82 |
| 2026-02-19 00:00 |
06:45:59.51 |
-13:25:40.8 |
HIP 32347 |
18.34 |
| 2026-02-19 12:00 |
06:45:57.92 |
-13:25:23.3 |
HIP 32347 |
17.87 |
| 2026-02-20 00:00 |
06:45:56.34 |
-13:25:05.7 |
HIP 32347 |
17.39 |
| 2026-02-20 12:00 |
06:45:54.78 |
-13:24:48.0 |
HIP 32347 |
16.91 |
| 2026-02-21 00:00 |
06:45:53.24 |
-13:24:30.2 |
HIP 32347 |
16.44 |
| 2026-02-21 12:00 |
06:45:51.71 |
-13:24:12.3 |
HIP 32347 |
15.97 |
| 2026-02-22 00:00 |
06:45:50.21 |
-13:23:54.3 |
HIP 32347 |
15.50 |
| 2026-02-22 12:00 |
06:45:48.72 |
-13:23:36.3 |
HIP 32347 |
15.03 |
| 2026-02-23 00:00 |
06:45:47.24 |
-13:23:18.1 |
HIP 32347 |
14.57 |
| 2026-02-23 12:00 |
06:45:45.79 |
-13:22:59.9 |
HIP 32347 |
14.11 |
| 2026-02-24 00:00 |
06:45:44.35 |
-13:22:41.5 |
HIP 32347 |
13.65 |