C/2013 X1 (PANSTARRS)
| Parameter |
Value |
| Designation |
C/2013 X1 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2016-04-20T17:29:19.973760Z |
| Orbit solution date (soln_date, UTC) |
2022-10-25T15:34:16Z |
| Obs used |
539 |
| NEO |
- |
| M1 |
10.700 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2015-12-20.0000000 |
| e |
1.00102603 |
| q (au) |
1.314236 |
| a (au) |
-1280.894658 |
| i (deg) |
163.231932 |
| Ω (om, deg) |
130.954864 |
| ω (w, deg) |
164.460665 |
| M (ma, deg) |
-0.002639 |
Magnitude
Scatter + Global Linear
$$
M_a = (9.081 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.081 |
| n |
2.000 |
| gf |
0.984 |
| gb |
-0.934 |
| k |
1.000 |
| δ90 |
9.991 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2013-10-17 |
2015-12-16 |
-0.3388 |
-0.216 |
| 2015-12-16 |
2016-01-10 |
+25.4658 |
-8.915 |
| 2016-01-10 |
2016-04-20 |
+10.9858 |
-4.062 |
| 2016-04-22 |
2018-01-29 |
+6.3808 |
-3.425 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
11:18:17.59 |
-07:58:08.5 |
HIP 55287 |
28.63 |
| 2026-02-03 12:00 |
11:18:13.45 |
-07:57:51.0 |
HIP 55287 |
28.98 |
| 2026-02-04 00:00 |
11:18:09.29 |
-07:57:33.2 |
HIP 55287 |
29.37 |
| 2026-02-04 12:00 |
11:18:05.11 |
-07:57:15.2 |
HIP 55287 |
29.79 |
| 2026-02-05 00:00 |
11:18:00.90 |
-07:56:56.9 |
HIP 55287 |
30.24 |
| 2026-02-05 12:00 |
11:17:56.67 |
-07:56:38.3 |
HIP 55287 |
30.72 |
| 2026-02-06 00:00 |
11:17:52.42 |
-07:56:19.5 |
HIP 55287 |
31.24 |
| 2026-02-06 12:00 |
11:17:48.14 |
-07:56:00.4 |
HIP 55287 |
31.78 |
| 2026-02-07 00:00 |
11:17:43.85 |
-07:55:41.0 |
HIP 55287 |
32.36 |
| 2026-02-07 12:00 |
11:17:39.53 |
-07:55:21.4 |
HIP 55287 |
32.97 |
| 2026-02-08 00:00 |
11:17:35.19 |
-07:55:01.6 |
HIP 55287 |
33.60 |
| 2026-02-08 12:00 |
11:17:30.82 |
-07:54:41.4 |
HIP 55287 |
34.26 |
| 2026-02-09 00:00 |
11:17:26.44 |
-07:54:21.1 |
HIP 55287 |
34.95 |
| 2026-02-09 12:00 |
11:17:22.04 |
-07:54:00.4 |
HIP 55287 |
35.66 |
| 2026-02-10 00:00 |
11:17:17.61 |
-07:53:39.6 |
HIP 55287 |
36.39 |
| 2026-02-10 12:00 |
11:17:13.17 |
-07:53:18.4 |
HIP 55287 |
37.15 |
| 2026-02-11 00:00 |
11:17:08.71 |
-07:52:57.0 |
HIP 55287 |
37.93 |
| 2026-02-11 12:00 |
11:17:04.23 |
-07:52:35.4 |
HIP 55287 |
38.73 |
| 2026-02-12 00:00 |
11:16:59.73 |
-07:52:13.5 |
HIP 55287 |
39.56 |
| 2026-02-12 12:00 |
11:16:55.21 |
-07:51:51.4 |
HIP 55287 |
40.40 |
| 2026-02-13 00:00 |
11:16:50.67 |
-07:51:29.0 |
HIP 55287 |
41.26 |
| 2026-02-13 12:00 |
11:16:46.11 |
-07:51:06.4 |
HIP 55287 |
42.14 |
| 2026-02-14 00:00 |
11:16:41.54 |
-07:50:43.6 |
HIP 55062 |
42.73 |
| 2026-02-14 12:00 |
11:16:36.95 |
-07:50:20.5 |
HIP 55062 |
42.22 |
| 2026-02-15 00:00 |
11:16:32.35 |
-07:49:57.2 |
HIP 55062 |
41.73 |
| 2026-02-15 12:00 |
11:16:27.73 |
-07:49:33.6 |
HIP 55062 |
41.27 |
| 2026-02-16 00:00 |
11:16:23.09 |
-07:49:09.8 |
HIP 55062 |
40.83 |
| 2026-02-16 12:00 |
11:16:18.44 |
-07:48:45.8 |
HIP 55062 |
40.42 |
| 2026-02-17 00:00 |
11:16:13.77 |
-07:48:21.5 |
HIP 55062 |
40.04 |
| 2026-02-17 12:00 |
11:16:09.09 |
-07:47:57.0 |
HIP 55062 |
39.69 |
| 2026-02-18 00:00 |
11:16:04.39 |
-07:47:32.3 |
HIP 55062 |
39.37 |
| 2026-02-18 12:00 |
11:15:59.68 |
-07:47:07.4 |
HIP 55062 |
39.09 |
| 2026-02-19 00:00 |
11:15:54.96 |
-07:46:42.2 |
HIP 55062 |
38.84 |
| 2026-02-19 12:00 |
11:15:50.22 |
-07:46:16.9 |
HIP 55062 |
38.63 |
| 2026-02-20 00:00 |
11:15:45.48 |
-07:45:51.3 |
HIP 55062 |
38.45 |
| 2026-02-20 12:00 |
11:15:40.72 |
-07:45:25.5 |
HIP 55062 |
38.31 |
| 2026-02-21 00:00 |
11:15:35.94 |
-07:44:59.4 |
HIP 55062 |
38.20 |
| 2026-02-21 12:00 |
11:15:31.16 |
-07:44:33.2 |
HIP 55062 |
38.14 |
| 2026-02-22 00:00 |
11:15:26.37 |
-07:44:06.8 |
HIP 55062 |
38.12 |
| 2026-02-22 12:00 |
11:15:21.56 |
-07:43:40.1 |
HIP 55062 |
38.13 |
| 2026-02-23 00:00 |
11:15:16.75 |
-07:43:13.3 |
HIP 55062 |
38.19 |
| 2026-02-23 12:00 |
11:15:11.92 |
-07:42:46.2 |
HIP 55062 |
38.29 |
| 2026-02-24 00:00 |
11:15:07.09 |
-07:42:19.0 |
HIP 55062 |
38.42 |