| Parameter |
Value |
| Designation |
C/2011 S2 (Kowalski) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2011-10-26T08:20:46.965120Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:56Z |
| Obs used |
343 |
| NEO |
Yes |
| M1 |
15.600 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2011-10-23.0000000 |
| e |
0.93161485 |
| q (au) |
1.115120 |
| a (au) |
16.306469 |
| i (deg) |
17.572538 |
| Ω (om, deg) |
288.070325 |
| ω (w, deg) |
192.189985 |
| M (ma, deg) |
359.949891 |
Magnitude
Scatter + Global Linear
$$
M_a = (15.975 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
15.975 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.701 |
| k |
0.800 |
| 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 |
19:13:05.83 |
-22:03:16.1 |
HIP 94510 |
14.59 |
| 2026-09-20 12:00 |
19:13:04.47 |
-22:03:17.6 |
HIP 94510 |
14.90 |
| 2026-09-21 00:00 |
19:13:03.15 |
-22:03:19.0 |
HIP 94510 |
15.21 |
| 2026-09-21 12:00 |
19:13:01.87 |
-22:03:20.3 |
HIP 94338 |
15.08 |
| 2026-09-22 00:00 |
19:13:00.63 |
-22:03:21.5 |
HIP 94338 |
14.84 |
| 2026-09-22 12:00 |
19:12:59.44 |
-22:03:22.7 |
HIP 94338 |
14.61 |
| 2026-09-23 00:00 |
19:12:58.29 |
-22:03:23.8 |
HIP 94338 |
14.40 |
| 2026-09-23 12:00 |
19:12:57.18 |
-22:03:24.9 |
HIP 94338 |
14.19 |
| 2026-09-24 00:00 |
19:12:56.11 |
-22:03:25.8 |
HIP 94338 |
13.99 |
| 2026-09-24 12:00 |
19:12:55.09 |
-22:03:26.7 |
HIP 94338 |
13.80 |
| 2026-09-25 00:00 |
19:12:54.11 |
-22:03:27.5 |
HIP 94338 |
13.62 |
| 2026-09-25 12:00 |
19:12:53.17 |
-22:03:28.3 |
HIP 94338 |
13.45 |
| 2026-09-26 00:00 |
19:12:52.27 |
-22:03:29.0 |
HIP 94338 |
13.29 |
| 2026-09-26 12:00 |
19:12:51.42 |
-22:03:29.6 |
HIP 94338 |
13.14 |
| 2026-09-27 00:00 |
19:12:50.61 |
-22:03:30.1 |
HIP 94338 |
12.99 |
| 2026-09-27 12:00 |
19:12:49.84 |
-22:03:30.5 |
HIP 94338 |
12.85 |
| 2026-09-28 00:00 |
19:12:49.12 |
-22:03:30.9 |
HIP 94338 |
12.73 |
| 2026-09-28 12:00 |
19:12:48.44 |
-22:03:31.2 |
HIP 94338 |
12.60 |
| 2026-09-29 00:00 |
19:12:47.80 |
-22:03:31.4 |
HIP 94338 |
12.49 |
| 2026-09-29 12:00 |
19:12:47.20 |
-22:03:31.6 |
HIP 94338 |
12.39 |
| 2026-09-30 00:00 |
19:12:46.65 |
-22:03:31.7 |
HIP 94338 |
12.29 |
| 2026-09-30 12:00 |
19:12:46.14 |
-22:03:31.7 |
HIP 94338 |
12.20 |
| 2026-10-01 00:00 |
19:12:45.67 |
-22:03:31.6 |
HIP 94338 |
12.11 |
| 2026-10-01 12:00 |
19:12:45.25 |
-22:03:31.5 |
HIP 94338 |
12.04 |
| 2026-10-02 00:00 |
19:12:44.87 |
-22:03:31.3 |
HIP 94338 |
11.97 |
| 2026-10-02 12:00 |
19:12:44.53 |
-22:03:31.0 |
HIP 94338 |
11.91 |
| 2026-10-03 00:00 |
19:12:44.24 |
-22:03:30.7 |
HIP 94338 |
11.85 |
| 2026-10-03 12:00 |
19:12:43.99 |
-22:03:30.2 |
HIP 94338 |
11.80 |
| 2026-10-04 00:00 |
19:12:43.78 |
-22:03:29.7 |
HIP 94338 |
11.76 |
| 2026-10-04 12:00 |
19:12:43.62 |
-22:03:29.1 |
HIP 94338 |
11.73 |
| 2026-10-05 00:00 |
19:12:43.50 |
-22:03:28.5 |
HIP 94338 |
11.70 |
| 2026-10-05 12:00 |
19:12:43.42 |
-22:03:27.8 |
HIP 94338 |
11.68 |
| 2026-10-06 00:00 |
19:12:43.39 |
-22:03:26.9 |
HIP 94338 |
11.66 |
| 2026-10-06 12:00 |
19:12:43.40 |
-22:03:26.1 |
HIP 94338 |
11.65 |
| 2026-10-07 00:00 |
19:12:43.46 |
-22:03:25.1 |
HIP 94338 |
11.65 |
| 2026-10-07 12:00 |
19:12:43.56 |
-22:03:24.1 |
HIP 94338 |
11.66 |
| 2026-10-08 00:00 |
19:12:43.70 |
-22:03:23.0 |
HIP 94338 |
11.67 |
| 2026-10-08 12:00 |
19:12:43.88 |
-22:03:21.8 |
HIP 94338 |
11.69 |
| 2026-10-09 00:00 |
19:12:44.11 |
-22:03:20.6 |
HIP 94338 |
11.72 |
| 2026-10-09 12:00 |
19:12:44.38 |
-22:03:19.2 |
HIP 94338 |
11.75 |
| 2026-10-10 00:00 |
19:12:44.70 |
-22:03:17.8 |
HIP 94338 |
11.79 |
| 2026-10-10 12:00 |
19:12:45.06 |
-22:03:16.3 |
HIP 94338 |
11.84 |
| 2026-10-11 00:00 |
19:12:45.46 |
-22:03:14.8 |
HIP 94338 |
11.90 |