C/2011 P2 (PANSTARRS)
| Parameter |
Value |
| Designation |
C/2011 P2 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2010-09-13T12:20:43.287360Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:54Z |
| Obs used |
58 |
| NEO |
- |
| M1 |
6.700 |
| K1 |
12.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2012-02-09.0000000 |
| e |
0.36981923 |
| q (au) |
6.148105 |
| a (au) |
9.756097 |
| i (deg) |
8.989636 |
| Ω (om, deg) |
204.018525 |
| ω (w, deg) |
76.384633 |
| M (ma, deg) |
16.608031 |
Magnitude
Scatter + Global Linear
$$
M_a = (3.498 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
3.498 |
| n |
6.000 |
| gf |
0.973 |
| gb |
-1.000 |
| k |
1.000 |
| 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) |
| 2026-02-03 00:00 |
06:35:55.60 |
+13:49:09.9 |
HIP 31531 |
7.82 |
| 2026-02-03 12:00 |
06:35:49.67 |
+13:49:27.4 |
HIP 31531 |
8.59 |
| 2026-02-04 00:00 |
06:35:43.80 |
+13:49:45.0 |
HIP 31495 |
9.42 |
| 2026-02-04 12:00 |
06:35:37.98 |
+13:50:02.6 |
HIP 31495 |
9.31 |
| 2026-02-05 00:00 |
06:35:32.22 |
+13:50:20.4 |
HIP 31495 |
9.41 |
| 2026-02-05 12:00 |
06:35:26.52 |
+13:50:38.2 |
HIP 31495 |
9.71 |
| 2026-02-06 00:00 |
06:35:20.87 |
+13:50:56.1 |
HIP 31495 |
10.20 |
| 2026-02-06 12:00 |
06:35:15.29 |
+13:51:14.2 |
HIP 31495 |
10.83 |
| 2026-02-07 00:00 |
06:35:09.75 |
+13:51:32.3 |
HIP 31495 |
11.59 |
| 2026-02-07 12:00 |
06:35:04.28 |
+13:51:50.5 |
HIP 31495 |
12.44 |
| 2026-02-08 00:00 |
06:34:58.87 |
+13:52:08.7 |
HIP 31495 |
13.36 |
| 2026-02-08 12:00 |
06:34:53.52 |
+13:52:27.1 |
HIP 31495 |
14.34 |
| 2026-02-09 00:00 |
06:34:48.22 |
+13:52:45.5 |
HIP 31495 |
15.35 |
| 2026-02-09 12:00 |
06:34:42.99 |
+13:53:04.1 |
HIP 31495 |
16.40 |
| 2026-02-10 00:00 |
06:34:37.82 |
+13:53:22.6 |
HIP 31495 |
17.46 |
| 2026-02-10 12:00 |
06:34:32.71 |
+13:53:41.3 |
HIP 31495 |
18.54 |
| 2026-02-11 00:00 |
06:34:27.67 |
+13:54:00.1 |
HIP 31495 |
19.63 |
| 2026-02-11 12:00 |
06:34:22.69 |
+13:54:18.9 |
HIP 31277 |
18.78 |
| 2026-02-12 00:00 |
06:34:17.77 |
+13:54:37.8 |
HIP 31277 |
17.82 |
| 2026-02-12 12:00 |
06:34:12.91 |
+13:54:56.7 |
HIP 31277 |
16.91 |
| 2026-02-13 00:00 |
06:34:08.13 |
+13:55:15.7 |
HIP 31277 |
16.05 |
| 2026-02-13 12:00 |
06:34:03.40 |
+13:55:34.8 |
HIP 31277 |
15.25 |
| 2026-02-14 00:00 |
06:33:58.74 |
+13:55:54.0 |
HIP 31277 |
14.50 |
| 2026-02-14 12:00 |
06:33:54.15 |
+13:56:13.2 |
HIP 31277 |
13.81 |
| 2026-02-15 00:00 |
06:33:49.63 |
+13:56:32.5 |
HIP 31277 |
13.19 |
| 2026-02-15 12:00 |
06:33:45.17 |
+13:56:51.8 |
HIP 31277 |
12.65 |
| 2026-02-16 00:00 |
06:33:40.78 |
+13:57:11.2 |
HIP 31277 |
12.19 |
| 2026-02-16 12:00 |
06:33:36.46 |
+13:57:30.6 |
HIP 31277 |
11.81 |
| 2026-02-17 00:00 |
06:33:32.21 |
+13:57:50.1 |
HIP 31277 |
11.53 |
| 2026-02-17 12:00 |
06:33:28.03 |
+13:58:09.6 |
HIP 31277 |
11.34 |
| 2026-02-18 00:00 |
06:33:23.92 |
+13:58:29.2 |
HIP 31277 |
11.24 |
| 2026-02-18 12:00 |
06:33:19.88 |
+13:58:48.8 |
HIP 31277 |
11.23 |
| 2026-02-19 00:00 |
06:33:15.91 |
+13:59:08.5 |
HIP 31277 |
11.31 |
| 2026-02-19 12:00 |
06:33:12.00 |
+13:59:28.2 |
HIP 31277 |
11.46 |
| 2026-02-20 00:00 |
06:33:08.18 |
+13:59:48.0 |
HIP 31277 |
11.70 |
| 2026-02-20 12:00 |
06:33:04.42 |
+14:00:07.7 |
HIP 31277 |
11.99 |
| 2026-02-21 00:00 |
06:33:00.73 |
+14:00:27.6 |
HIP 31277 |
12.35 |
| 2026-02-21 12:00 |
06:32:57.12 |
+14:00:47.4 |
HIP 31277 |
12.75 |
| 2026-02-22 00:00 |
06:32:53.58 |
+14:01:07.3 |
HIP 31277 |
13.19 |
| 2026-02-22 12:00 |
06:32:50.12 |
+14:01:27.2 |
HIP 31277 |
13.66 |
| 2026-02-23 00:00 |
06:32:46.72 |
+14:01:47.1 |
HIP 31277 |
14.16 |
| 2026-02-23 12:00 |
06:32:43.40 |
+14:02:07.1 |
HIP 31277 |
14.68 |
| 2026-02-24 00:00 |
06:32:40.16 |
+14:02:27.1 |
HIP 31277 |
15.22 |