| Parameter |
Value |
| Designation |
C/2013 Y2 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2014-06-13T15:29:33.463680Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:44Z |
| Obs used |
436 |
| NEO |
- |
| M1 |
9.700 |
| K1 |
15.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2014-03-11.0000000 |
| e |
0.99127402 |
| q (au) |
1.919085 |
| a (au) |
219.927835 |
| i (deg) |
29.414744 |
| Ω (om, deg) |
243.400925 |
| ω (w, deg) |
308.841643 |
| M (ma, deg) |
359.971399 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.343 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.343 |
| n |
6.000 |
| gf |
0.855 |
| gb |
-0.679 |
| k |
0.919 |
| δ90 |
1.000 |
| 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) |
| 2026-09-25 00:00 |
22:11:11.00 |
+21:04:22.5 |
HIP 109458 |
11.10 |
| 2026-09-25 12:00 |
22:11:07.60 |
+21:03:48.6 |
HIP 109458 |
10.13 |
| 2026-09-26 00:00 |
22:11:04.23 |
+21:03:14.5 |
HIP 109458 |
9.16 |
| 2026-09-26 12:00 |
22:11:00.88 |
+21:02:40.2 |
HIP 109458 |
8.20 |
| 2026-09-27 00:00 |
22:10:57.56 |
+21:02:05.8 |
HIP 109458 |
7.24 |
| 2026-09-27 12:00 |
22:10:54.25 |
+21:01:31.2 |
HIP 109458 |
6.29 |
| 2026-09-28 00:00 |
22:10:50.97 |
+21:00:56.5 |
HIP 109458 |
5.35 |
| 2026-09-28 12:00 |
22:10:47.70 |
+21:00:21.6 |
HIP 109458 |
4.42 |
| 2026-09-29 00:00 |
22:10:44.47 |
+20:59:46.6 |
HIP 109458 |
3.51 |
| 2026-09-29 12:00 |
22:10:41.25 |
+20:59:11.5 |
HIP 109458 |
2.63 |
| 2026-09-30 00:00 |
22:10:38.06 |
+20:58:36.2 |
HIP 109458 |
1.84 |
| 2026-09-30 12:00 |
22:10:34.89 |
+20:58:00.8 |
HIP 109458 |
1.29 |
| 2026-10-01 00:00 |
22:10:31.75 |
+20:57:25.2 |
HIP 109458 |
1.31 |
| 2026-10-01 12:00 |
22:10:28.63 |
+20:56:49.5 |
HIP 109458 |
1.89 |
| 2026-10-02 00:00 |
22:10:25.53 |
+20:56:13.7 |
HIP 109458 |
2.68 |
| 2026-10-02 12:00 |
22:10:22.46 |
+20:55:37.8 |
HIP 109458 |
3.54 |
| 2026-10-03 00:00 |
22:10:19.41 |
+20:55:01.7 |
HIP 109458 |
4.43 |
| 2026-10-03 12:00 |
22:10:16.39 |
+20:54:25.5 |
HIP 109458 |
5.34 |
| 2026-10-04 00:00 |
22:10:13.39 |
+20:53:49.2 |
HIP 109458 |
6.24 |
| 2026-10-04 12:00 |
22:10:10.42 |
+20:53:12.8 |
HIP 109458 |
7.15 |
| 2026-10-05 00:00 |
22:10:07.48 |
+20:52:36.3 |
HIP 109458 |
8.06 |
| 2026-10-05 12:00 |
22:10:04.56 |
+20:51:59.7 |
HIP 109458 |
8.97 |
| 2026-10-06 00:00 |
22:10:01.67 |
+20:51:22.9 |
HIP 109458 |
9.88 |
| 2026-10-06 12:00 |
22:09:58.80 |
+20:50:46.1 |
HIP 109458 |
10.78 |
| 2026-10-07 00:00 |
22:09:55.97 |
+20:50:09.2 |
HIP 109458 |
11.69 |
| 2026-10-07 12:00 |
22:09:53.16 |
+20:49:32.2 |
HIP 109458 |
12.59 |
| 2026-10-08 00:00 |
22:09:50.37 |
+20:48:55.1 |
HIP 109458 |
13.48 |
| 2026-10-08 12:00 |
22:09:47.62 |
+20:48:17.9 |
HIP 109458 |
14.38 |
| 2026-10-09 00:00 |
22:09:44.89 |
+20:47:40.6 |
HIP 109458 |
15.26 |
| 2026-10-09 12:00 |
22:09:42.19 |
+20:47:03.2 |
HIP 109458 |
16.15 |
| 2026-10-10 00:00 |
22:09:39.52 |
+20:46:25.8 |
HIP 109458 |
17.03 |
| 2026-10-10 12:00 |
22:09:36.88 |
+20:45:48.3 |
HIP 109458 |
17.91 |
| 2026-10-11 00:00 |
22:09:34.27 |
+20:45:10.7 |
HIP 109458 |
18.79 |
| 2026-10-11 12:00 |
22:09:31.69 |
+20:44:33.1 |
HIP 109458 |
19.66 |
| 2026-10-12 00:00 |
22:09:29.13 |
+20:43:55.4 |
HIP 109458 |
20.52 |
| 2026-10-12 12:00 |
22:09:26.61 |
+20:43:17.6 |
HIP 109458 |
21.39 |
| 2026-10-13 00:00 |
22:09:24.12 |
+20:42:39.8 |
HIP 109458 |
22.24 |
| 2026-10-13 12:00 |
22:09:21.66 |
+20:42:01.9 |
HIP 109458 |
23.10 |
| 2026-10-14 00:00 |
22:09:19.22 |
+20:41:24.0 |
HIP 109458 |
23.95 |
| 2026-10-14 12:00 |
22:09:16.82 |
+20:40:46.0 |
HIP 109458 |
24.79 |
| 2026-10-15 00:00 |
22:09:14.45 |
+20:40:08.0 |
HIP 109458 |
25.64 |
| 2026-10-15 12:00 |
22:09:12.11 |
+20:39:30.0 |
HIP 109458 |
26.47 |
| 2026-10-16 00:00 |
22:09:09.80 |
+20:38:51.9 |
HIP 109458 |
27.30 |