| 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
$$
M_a = (9.102 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.102 |
| n |
2.000 |
| gf |
0.800 |
| gb |
-0.501 |
| k |
1.000 |
| δ90 |
7.925 |
| 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 |
-0.6277 |
-0.078 |
| 2015-12-16 |
2016-01-10 |
+25.7189 |
-8.969 |
| 2016-01-10 |
2016-04-20 |
+10.9684 |
-4.036 |
| 2016-04-22 |
2018-01-29 |
+6.2809 |
-3.385 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
11:04:42.84 |
-06:18:38.0 |
HIP 54207 |
13.33 |
| 2026-05-12 12:00 |
11:04:40.79 |
-06:18:10.3 |
HIP 54207 |
14.01 |
| 2026-05-13 00:00 |
11:04:38.77 |
-06:17:42.8 |
HIP 54207 |
14.68 |
| 2026-05-13 12:00 |
11:04:36.79 |
-06:17:15.5 |
HIP 54207 |
15.35 |
| 2026-05-14 00:00 |
11:04:34.85 |
-06:16:48.4 |
HIP 54207 |
16.01 |
| 2026-05-14 12:00 |
11:04:32.94 |
-06:16:21.5 |
HIP 54207 |
16.66 |
| 2026-05-15 00:00 |
11:04:31.07 |
-06:15:54.8 |
HIP 54207 |
17.30 |
| 2026-05-15 12:00 |
11:04:29.24 |
-06:15:28.2 |
HIP 54207 |
17.93 |
| 2026-05-16 00:00 |
11:04:27.44 |
-06:15:01.9 |
HIP 54207 |
18.55 |
| 2026-05-16 12:00 |
11:04:25.68 |
-06:14:35.7 |
HIP 54207 |
19.17 |
| 2026-05-17 00:00 |
11:04:23.96 |
-06:14:09.8 |
HIP 54207 |
19.77 |
| 2026-05-17 12:00 |
11:04:22.27 |
-06:13:44.0 |
HIP 54207 |
20.37 |
| 2026-05-18 00:00 |
11:04:20.63 |
-06:13:18.4 |
HIP 54207 |
20.95 |
| 2026-05-18 12:00 |
11:04:19.01 |
-06:12:53.1 |
HIP 54207 |
21.53 |
| 2026-05-19 00:00 |
11:04:17.44 |
-06:12:27.9 |
HIP 54207 |
22.10 |
| 2026-05-19 12:00 |
11:04:15.90 |
-06:12:02.9 |
HIP 54207 |
22.66 |
| 2026-05-20 00:00 |
11:04:14.40 |
-06:11:38.2 |
HIP 54207 |
23.21 |
| 2026-05-20 12:00 |
11:04:12.94 |
-06:11:13.6 |
HIP 54207 |
23.75 |
| 2026-05-21 00:00 |
11:04:11.52 |
-06:10:49.3 |
HIP 54207 |
24.28 |
| 2026-05-21 12:00 |
11:04:10.13 |
-06:10:25.1 |
HIP 53995 |
24.73 |
| 2026-05-22 00:00 |
11:04:08.78 |
-06:10:01.2 |
HIP 53995 |
24.66 |
| 2026-05-22 12:00 |
11:04:07.47 |
-06:09:37.5 |
HIP 53995 |
24.62 |
| 2026-05-23 00:00 |
11:04:06.20 |
-06:09:13.9 |
HIP 53995 |
24.58 |
| 2026-05-23 12:00 |
11:04:04.96 |
-06:08:50.7 |
HIP 53995 |
24.57 |
| 2026-05-24 00:00 |
11:04:03.76 |
-06:08:27.6 |
HIP 53995 |
24.56 |
| 2026-05-24 12:00 |
11:04:02.60 |
-06:08:04.7 |
HIP 53995 |
24.58 |
| 2026-05-25 00:00 |
11:04:01.47 |
-06:07:42.0 |
HIP 53995 |
24.60 |
| 2026-05-25 12:00 |
11:04:00.38 |
-06:07:19.6 |
HIP 53995 |
24.64 |
| 2026-05-26 00:00 |
11:03:59.33 |
-06:06:57.4 |
HIP 53995 |
24.70 |
| 2026-05-26 12:00 |
11:03:58.32 |
-06:06:35.4 |
HIP 53995 |
24.76 |
| 2026-05-27 00:00 |
11:03:57.34 |
-06:06:13.6 |
HIP 53995 |
24.84 |
| 2026-05-27 12:00 |
11:03:56.41 |
-06:05:52.1 |
HIP 53995 |
24.93 |
| 2026-05-28 00:00 |
11:03:55.51 |
-06:05:30.7 |
HIP 53995 |
25.03 |
| 2026-05-28 12:00 |
11:03:54.64 |
-06:05:09.6 |
HIP 53995 |
25.14 |
| 2026-05-29 00:00 |
11:03:53.82 |
-06:04:48.7 |
HIP 53995 |
25.26 |
| 2026-05-29 12:00 |
11:03:53.03 |
-06:04:28.0 |
HIP 53995 |
25.39 |
| 2026-05-30 00:00 |
11:03:52.27 |
-06:04:07.6 |
HIP 53995 |
25.52 |
| 2026-05-30 12:00 |
11:03:51.56 |
-06:03:47.4 |
HIP 53995 |
25.67 |
| 2026-05-31 00:00 |
11:03:50.88 |
-06:03:27.4 |
HIP 53995 |
25.82 |
| 2026-05-31 12:00 |
11:03:50.24 |
-06:03:07.6 |
HIP 53995 |
25.98 |
| 2026-06-01 00:00 |
11:03:49.64 |
-06:02:48.1 |
HIP 53995 |
26.15 |
| 2026-06-01 12:00 |
11:03:49.07 |
-06:02:28.8 |
HIP 53995 |
26.32 |
| 2026-06-02 00:00 |
11:03:48.54 |
-06:02:09.7 |
HIP 53995 |
26.50 |