| Parameter |
Value |
| Designation |
P/2009 Y2 (Kowalski) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2010-03-30T16:39:00.302400Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:38Z |
| Obs used |
178 |
| NEO |
- |
| M1 |
6.200 |
| K1 |
28.750 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2010-01-11.0000000 |
| e |
0.64052556 |
| q (au) |
2.339193 |
| a (au) |
6.507258 |
| i (deg) |
29.929609 |
| Ω (om, deg) |
262.126517 |
| ω (w, deg) |
171.961934 |
| M (ma, deg) |
355.327521 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.523 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.523 |
| n |
6.000 |
| gf |
0.991 |
| gb |
-0.502 |
| k |
1.000 |
| δ90 |
9.996 |
| 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 |
04:39:46.67 |
+42:48:26.9 |
HIP 21614 |
17.82 |
| 2026-09-20 12:00 |
04:40:21.75 |
+42:48:02.9 |
HIP 21614 |
23.64 |
| 2026-09-21 00:00 |
04:40:56.46 |
+42:47:36.6 |
HIP 21614 |
29.67 |
| 2026-09-21 12:00 |
04:41:30.80 |
+42:47:08.0 |
HIP 22019 |
35.62 |
| 2026-09-22 00:00 |
04:42:04.77 |
+42:46:37.0 |
HIP 22019 |
30.58 |
| 2026-09-22 12:00 |
04:42:38.36 |
+42:46:03.7 |
HIP 22019 |
26.10 |
| 2026-09-23 00:00 |
04:43:11.58 |
+42:45:28.0 |
HIP 22019 |
22.43 |
| 2026-09-23 12:00 |
04:43:44.41 |
+42:44:49.9 |
HIP 22019 |
20.00 |
| 2026-09-24 00:00 |
04:44:16.85 |
+42:44:09.5 |
HIP 22019 |
19.19 |
| 2026-09-24 12:00 |
04:44:48.90 |
+42:43:26.6 |
HIP 22095 |
17.61 |
| 2026-09-25 00:00 |
04:45:20.56 |
+42:42:41.4 |
HIP 22095 |
16.07 |
| 2026-09-25 12:00 |
04:45:51.82 |
+42:41:53.7 |
HIP 22095 |
16.54 |
| 2026-09-26 00:00 |
04:46:22.68 |
+42:41:03.5 |
HIP 22095 |
18.80 |
| 2026-09-26 12:00 |
04:46:53.14 |
+42:40:10.9 |
HIP 22196 |
19.88 |
| 2026-09-27 00:00 |
04:47:23.18 |
+42:39:15.9 |
HIP 22337 |
14.30 |
| 2026-09-27 12:00 |
04:47:52.82 |
+42:38:18.3 |
HIP 22337 |
8.79 |
| 2026-09-28 00:00 |
04:48:22.03 |
+42:37:18.3 |
HIP 22337 |
3.43 |
| 2026-09-28 12:00 |
04:48:50.83 |
+42:36:15.7 |
HIP 22337 |
2.37 |
| 2026-09-29 00:00 |
04:49:19.21 |
+42:35:10.6 |
HIP 22337 |
7.53 |
| 2026-09-29 12:00 |
04:49:47.16 |
+42:34:02.9 |
HIP 22337 |
12.76 |
| 2026-09-30 00:00 |
04:50:14.67 |
+42:32:52.6 |
HIP 22580 |
15.48 |
| 2026-09-30 12:00 |
04:50:41.75 |
+42:31:39.8 |
HIP 22580 |
11.71 |
| 2026-10-01 00:00 |
04:51:08.39 |
+42:30:24.4 |
HIP 22580 |
9.42 |
| 2026-10-01 12:00 |
04:51:34.59 |
+42:29:06.3 |
HIP 22580 |
9.61 |
| 2026-10-02 00:00 |
04:52:00.34 |
+42:27:45.6 |
HIP 22618 |
9.86 |
| 2026-10-02 12:00 |
04:52:25.64 |
+42:26:22.2 |
HIP 22699 |
9.72 |
| 2026-10-03 00:00 |
04:52:50.49 |
+42:24:56.1 |
HIP 22699 |
10.27 |
| 2026-10-03 12:00 |
04:53:14.88 |
+42:23:27.3 |
HIP 22699 |
12.76 |
| 2026-10-04 00:00 |
04:53:38.80 |
+42:21:55.8 |
HIP 22726 |
15.60 |
| 2026-10-04 12:00 |
04:54:02.26 |
+42:20:21.5 |
HIP 22726 |
15.75 |
| 2026-10-05 00:00 |
04:54:25.25 |
+42:18:44.5 |
HIP 22901 |
16.98 |
| 2026-10-05 12:00 |
04:54:47.76 |
+42:17:04.7 |
HIP 22901 |
12.87 |
| 2026-10-06 00:00 |
04:55:09.80 |
+42:15:22.0 |
HIP 22901 |
9.12 |
| 2026-10-06 12:00 |
04:55:31.36 |
+42:13:36.5 |
HIP 22901 |
6.27 |
| 2026-10-07 00:00 |
04:55:52.43 |
+42:11:48.1 |
HIP 22901 |
5.69 |
| 2026-10-07 12:00 |
04:56:13.02 |
+42:09:56.8 |
HIP 22901 |
7.81 |
| 2026-10-08 00:00 |
04:56:33.12 |
+42:08:02.6 |
HIP 22901 |
11.12 |
| 2026-10-08 12:00 |
04:56:52.72 |
+42:06:05.5 |
HIP 22901 |
14.79 |
| 2026-10-09 00:00 |
04:57:11.83 |
+42:04:05.4 |
HIP 22901 |
18.57 |
| 2026-10-09 12:00 |
04:57:30.44 |
+42:02:02.2 |
HIP 22901 |
22.38 |
| 2026-10-10 00:00 |
04:57:48.55 |
+41:59:56.1 |
HIP 23213 |
22.54 |
| 2026-10-10 12:00 |
04:58:06.16 |
+41:57:46.9 |
HIP 23213 |
18.77 |
| 2026-10-11 00:00 |
04:58:23.26 |
+41:55:34.7 |
HIP 23213 |
15.14 |