| Parameter |
Value |
| Designation |
C/2011 Q1 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2011-06-29T10:55:01.718400Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:54Z |
| Obs used |
59 |
| NEO |
- |
| M1 |
7.500 |
| K1 |
10.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2011-09-21.0000000 |
| e |
0.99791265 |
| q (au) |
6.780085 |
| a (au) |
3248.185456 |
| i (deg) |
94.862014 |
| Ω (om, deg) |
142.243907 |
| ω (w, deg) |
135.926448 |
| M (ma, deg) |
0.000445 |
Magnitude
Scatter + Global Linear
$$
M_a = (2.217 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
2.217 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.968 |
| 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) |
| 2026-05-12 00:00 |
03:58:03.25 |
-74:11:18.1 |
HIP 18362 |
17.56 |
| 2026-05-12 12:00 |
03:58:19.62 |
-74:11:06.6 |
HIP 18362 |
18.08 |
| 2026-05-13 00:00 |
03:58:36.01 |
-74:10:55.4 |
HIP 18362 |
18.67 |
| 2026-05-13 12:00 |
03:58:52.41 |
-74:10:44.7 |
HIP 18362 |
19.31 |
| 2026-05-14 00:00 |
03:59:08.82 |
-74:10:34.5 |
HIP 18362 |
20.00 |
| 2026-05-14 12:00 |
03:59:25.25 |
-74:10:24.7 |
HIP 18362 |
20.73 |
| 2026-05-15 00:00 |
03:59:41.69 |
-74:10:15.3 |
HIP 18362 |
21.51 |
| 2026-05-15 12:00 |
03:59:58.15 |
-74:10:06.3 |
HIP 18362 |
22.32 |
| 2026-05-16 00:00 |
04:00:14.62 |
-74:09:57.8 |
HIP 18362 |
23.16 |
| 2026-05-16 12:00 |
04:00:31.10 |
-74:09:49.8 |
HIP 18362 |
24.04 |
| 2026-05-17 00:00 |
04:00:47.59 |
-74:09:42.2 |
HIP 18362 |
24.94 |
| 2026-05-17 12:00 |
04:01:04.09 |
-74:09:35.0 |
HIP 18362 |
25.86 |
| 2026-05-18 00:00 |
04:01:20.60 |
-74:09:28.3 |
HIP 18362 |
26.80 |
| 2026-05-18 12:00 |
04:01:37.12 |
-74:09:22.0 |
HIP 18362 |
27.77 |
| 2026-05-19 00:00 |
04:01:53.64 |
-74:09:16.2 |
HIP 18362 |
28.75 |
| 2026-05-19 12:00 |
04:02:10.17 |
-74:09:10.8 |
HIP 18362 |
29.74 |
| 2026-05-20 00:00 |
04:02:26.71 |
-74:09:05.8 |
HIP 18362 |
30.75 |
| 2026-05-20 12:00 |
04:02:43.25 |
-74:09:01.3 |
HIP 18362 |
31.77 |
| 2026-05-21 00:00 |
04:02:59.80 |
-74:08:57.2 |
HIP 18362 |
32.80 |
| 2026-05-21 12:00 |
04:03:16.35 |
-74:08:53.6 |
HIP 18362 |
33.84 |
| 2026-05-22 00:00 |
04:03:32.91 |
-74:08:50.4 |
HIP 18362 |
34.89 |
| 2026-05-22 12:00 |
04:03:49.46 |
-74:08:47.7 |
HIP 18362 |
35.95 |
| 2026-05-23 00:00 |
04:04:06.02 |
-74:08:45.3 |
HIP 18362 |
37.01 |
| 2026-05-23 12:00 |
04:04:22.58 |
-74:08:43.5 |
HIP 18362 |
38.08 |
| 2026-05-24 00:00 |
04:04:39.14 |
-74:08:42.0 |
HIP 18362 |
39.16 |
| 2026-05-24 12:00 |
04:04:55.70 |
-74:08:41.1 |
HIP 18362 |
40.24 |
| 2026-05-25 00:00 |
04:05:12.26 |
-74:08:40.5 |
HIP 19671 |
39.38 |
| 2026-05-25 12:00 |
04:05:28.81 |
-74:08:40.4 |
HIP 19671 |
38.47 |
| 2026-05-26 00:00 |
04:05:45.37 |
-74:08:40.7 |
HIP 19671 |
37.57 |
| 2026-05-26 12:00 |
04:06:01.92 |
-74:08:41.5 |
HIP 19671 |
36.69 |
| 2026-05-27 00:00 |
04:06:18.47 |
-74:08:42.7 |
HIP 19671 |
35.83 |
| 2026-05-27 12:00 |
04:06:35.01 |
-74:08:44.3 |
HIP 19671 |
34.99 |
| 2026-05-28 00:00 |
04:06:51.55 |
-74:08:46.4 |
HIP 19671 |
34.17 |
| 2026-05-28 12:00 |
04:07:08.09 |
-74:08:48.9 |
HIP 19671 |
33.38 |
| 2026-05-29 00:00 |
04:07:24.62 |
-74:08:51.8 |
HIP 19671 |
32.61 |
| 2026-05-29 12:00 |
04:07:41.14 |
-74:08:55.2 |
HIP 19671 |
31.87 |
| 2026-05-30 00:00 |
04:07:57.66 |
-74:08:59.0 |
HIP 19671 |
31.17 |
| 2026-05-30 12:00 |
04:08:14.16 |
-74:09:03.2 |
HIP 19671 |
30.49 |
| 2026-05-31 00:00 |
04:08:30.66 |
-74:09:07.9 |
HIP 19671 |
29.85 |
| 2026-05-31 12:00 |
04:08:47.15 |
-74:09:13.0 |
HIP 19671 |
29.25 |
| 2026-06-01 00:00 |
04:09:03.63 |
-74:09:18.6 |
HIP 19671 |
28.69 |
| 2026-06-01 12:00 |
04:09:20.11 |
-74:09:24.5 |
HIP 19671 |
28.16 |
| 2026-06-02 00:00 |
04:09:36.57 |
-74:09:30.9 |
HIP 19671 |
27.69 |