| 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) |
| 2026-05-12 00:00 |
19:29:44.18 |
-21:36:29.7 |
HIP 95855 |
16.17 |
| 2026-05-12 12:00 |
19:29:41.90 |
-21:36:33.0 |
HIP 95855 |
16.23 |
| 2026-05-13 00:00 |
19:29:39.57 |
-21:36:36.4 |
HIP 95855 |
16.31 |
| 2026-05-13 12:00 |
19:29:37.21 |
-21:36:39.9 |
HIP 95855 |
16.41 |
| 2026-05-14 00:00 |
19:29:34.80 |
-21:36:43.4 |
HIP 95855 |
16.52 |
| 2026-05-14 12:00 |
19:29:32.36 |
-21:36:47.1 |
HIP 95855 |
16.66 |
| 2026-05-15 00:00 |
19:29:29.88 |
-21:36:50.8 |
HIP 95855 |
16.82 |
| 2026-05-15 12:00 |
19:29:27.36 |
-21:36:54.6 |
HIP 95855 |
17.00 |
| 2026-05-16 00:00 |
19:29:24.81 |
-21:36:58.5 |
HIP 95855 |
17.20 |
| 2026-05-16 12:00 |
19:29:22.22 |
-21:37:02.4 |
HIP 95855 |
17.43 |
| 2026-05-17 00:00 |
19:29:19.59 |
-21:37:06.5 |
HIP 95855 |
17.68 |
| 2026-05-17 12:00 |
19:29:16.92 |
-21:37:10.6 |
HIP 95855 |
17.94 |
| 2026-05-18 00:00 |
19:29:14.21 |
-21:37:14.8 |
HIP 95855 |
18.23 |
| 2026-05-18 12:00 |
19:29:11.47 |
-21:37:19.1 |
HIP 95855 |
18.55 |
| 2026-05-19 00:00 |
19:29:08.69 |
-21:37:23.4 |
HIP 95855 |
18.88 |
| 2026-05-19 12:00 |
19:29:05.88 |
-21:37:27.8 |
HIP 95855 |
19.23 |
| 2026-05-20 00:00 |
19:29:03.02 |
-21:37:32.3 |
HIP 95855 |
19.61 |
| 2026-05-20 12:00 |
19:29:00.14 |
-21:37:36.9 |
HIP 95855 |
20.01 |
| 2026-05-21 00:00 |
19:28:57.21 |
-21:37:41.6 |
HIP 95855 |
20.42 |
| 2026-05-21 12:00 |
19:28:54.26 |
-21:37:46.3 |
HIP 95855 |
20.86 |
| 2026-05-22 00:00 |
19:28:51.26 |
-21:37:51.1 |
HIP 95855 |
21.31 |
| 2026-05-22 12:00 |
19:28:48.24 |
-21:37:55.9 |
HIP 95855 |
21.79 |
| 2026-05-23 00:00 |
19:28:45.17 |
-21:38:00.9 |
HIP 95855 |
22.28 |
| 2026-05-23 12:00 |
19:28:42.08 |
-21:38:05.9 |
HIP 95855 |
22.79 |
| 2026-05-24 00:00 |
19:28:38.95 |
-21:38:10.9 |
HIP 95855 |
23.32 |
| 2026-05-24 12:00 |
19:28:35.78 |
-21:38:16.1 |
HIP 95855 |
23.86 |
| 2026-05-25 00:00 |
19:28:32.58 |
-21:38:21.3 |
HIP 95855 |
24.42 |
| 2026-05-25 12:00 |
19:28:29.35 |
-21:38:26.6 |
HIP 95855 |
25.00 |
| 2026-05-26 00:00 |
19:28:26.09 |
-21:38:31.9 |
HIP 95855 |
25.59 |
| 2026-05-26 12:00 |
19:28:22.79 |
-21:38:37.3 |
HIP 95855 |
26.20 |
| 2026-05-27 00:00 |
19:28:19.46 |
-21:38:42.8 |
HIP 95855 |
26.82 |
| 2026-05-27 12:00 |
19:28:16.10 |
-21:38:48.3 |
HIP 95855 |
27.46 |
| 2026-05-28 00:00 |
19:28:12.71 |
-21:38:53.9 |
HIP 95564 |
27.48 |
| 2026-05-28 12:00 |
19:28:09.28 |
-21:38:59.6 |
HIP 95564 |
26.69 |
| 2026-05-29 00:00 |
19:28:05.82 |
-21:39:05.3 |
HIP 95564 |
25.89 |
| 2026-05-29 12:00 |
19:28:02.34 |
-21:39:11.1 |
HIP 95564 |
25.09 |
| 2026-05-30 00:00 |
19:27:58.82 |
-21:39:17.0 |
HIP 95564 |
24.28 |
| 2026-05-30 12:00 |
19:27:55.27 |
-21:39:22.9 |
HIP 95564 |
23.47 |
| 2026-05-31 00:00 |
19:27:51.69 |
-21:39:28.9 |
HIP 95564 |
22.64 |
| 2026-05-31 12:00 |
19:27:48.08 |
-21:39:34.9 |
HIP 95564 |
21.82 |
| 2026-06-01 00:00 |
19:27:44.44 |
-21:39:41.0 |
HIP 95564 |
20.99 |
| 2026-06-01 12:00 |
19:27:40.77 |
-21:39:47.1 |
HIP 95564 |
20.15 |
| 2026-06-02 00:00 |
19:27:37.07 |
-21:39:53.3 |
HIP 95564 |
19.31 |