| Parameter |
Value |
| Designation |
C/2012 X1 (LINEAR) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2014-02-21T15:12:12.525120Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:29Z |
| Obs used |
2560 |
| NEO |
- |
| M1 |
5.500 |
| K1 |
14.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2013-12-18.0000000 |
| e |
0.98957208 |
| q (au) |
1.598910 |
| a (au) |
153.329748 |
| i (deg) |
44.367326 |
| Ω (om, deg) |
113.146428 |
| ω (w, deg) |
132.113677 |
| M (ma, deg) |
359.965929 |
Magnitude
Scatter + Global Linear
$$
M_a = (7.004 + 5.465\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
7.004 |
| n |
5.465 |
| gf |
1.000 |
| gb |
-0.669 |
| k |
0.933 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2012-12-08 |
2013-11-20 |
+5.9231 |
-3.732 |
| 2013-11-20 |
2014-02-20 |
+6.3516 |
-2.844 |
| 2014-02-22 |
2015-12-09 |
+1.6210 |
-2.089 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
03:31:07.56 |
-23:45:41.5 |
HIP 16312 |
12.26 |
| 2026-03-26 12:00 |
03:31:10.67 |
-23:44:59.1 |
HIP 16312 |
12.93 |
| 2026-03-27 00:00 |
03:31:13.80 |
-23:44:17.0 |
HIP 16312 |
13.65 |
| 2026-03-27 12:00 |
03:31:16.96 |
-23:43:35.0 |
HIP 16312 |
14.41 |
| 2026-03-28 00:00 |
03:31:20.15 |
-23:42:53.2 |
HIP 16312 |
15.21 |
| 2026-03-28 12:00 |
03:31:23.37 |
-23:42:11.6 |
HIP 16312 |
16.03 |
| 2026-03-29 00:00 |
03:31:26.61 |
-23:41:30.2 |
HIP 16510 |
16.21 |
| 2026-03-29 12:00 |
03:31:29.87 |
-23:40:49.0 |
HIP 16510 |
15.33 |
| 2026-03-30 00:00 |
03:31:33.17 |
-23:40:08.0 |
HIP 16510 |
14.46 |
| 2026-03-30 12:00 |
03:31:36.49 |
-23:39:27.2 |
HIP 16510 |
13.61 |
| 2026-03-31 00:00 |
03:31:39.83 |
-23:38:46.6 |
HIP 16510 |
12.78 |
| 2026-03-31 12:00 |
03:31:43.20 |
-23:38:06.2 |
HIP 16510 |
11.97 |
| 2026-04-01 00:00 |
03:31:46.59 |
-23:37:26.0 |
HIP 16510 |
11.19 |
| 2026-04-01 12:00 |
03:31:50.01 |
-23:36:46.0 |
HIP 16510 |
10.45 |
| 2026-04-02 00:00 |
03:31:53.46 |
-23:36:06.2 |
HIP 16510 |
9.75 |
| 2026-04-02 12:00 |
03:31:56.92 |
-23:35:26.6 |
HIP 16510 |
9.11 |
| 2026-04-03 00:00 |
03:32:00.42 |
-23:34:47.3 |
HIP 16510 |
8.55 |
| 2026-04-03 12:00 |
03:32:03.93 |
-23:34:08.1 |
HIP 16510 |
8.06 |
| 2026-04-04 00:00 |
03:32:07.47 |
-23:33:29.2 |
HIP 16510 |
7.68 |
| 2026-04-04 12:00 |
03:32:11.03 |
-23:32:50.5 |
HIP 16510 |
7.43 |
| 2026-04-05 00:00 |
03:32:14.62 |
-23:32:12.0 |
HIP 16510 |
7.30 |
| 2026-04-05 12:00 |
03:32:18.22 |
-23:31:33.7 |
HIP 16510 |
7.32 |
| 2026-04-06 00:00 |
03:32:21.85 |
-23:30:55.7 |
HIP 16510 |
7.48 |
| 2026-04-06 12:00 |
03:32:25.51 |
-23:30:17.8 |
HIP 16510 |
7.77 |
| 2026-04-07 00:00 |
03:32:29.18 |
-23:29:40.3 |
HIP 16510 |
8.18 |
| 2026-04-07 12:00 |
03:32:32.88 |
-23:29:02.9 |
HIP 16510 |
8.70 |
| 2026-04-08 00:00 |
03:32:36.60 |
-23:28:25.8 |
HIP 16510 |
9.30 |
| 2026-04-08 12:00 |
03:32:40.34 |
-23:27:48.9 |
HIP 16510 |
9.98 |
| 2026-04-09 00:00 |
03:32:44.10 |
-23:27:12.2 |
HIP 16510 |
10.71 |
| 2026-04-09 12:00 |
03:32:47.88 |
-23:26:35.8 |
HIP 16510 |
11.49 |
| 2026-04-10 00:00 |
03:32:51.68 |
-23:25:59.7 |
HIP 16510 |
12.31 |
| 2026-04-10 12:00 |
03:32:55.51 |
-23:25:23.8 |
HIP 16510 |
13.16 |
| 2026-04-11 00:00 |
03:32:59.35 |
-23:24:48.1 |
HIP 16510 |
14.04 |
| 2026-04-11 12:00 |
03:33:03.21 |
-23:24:12.7 |
HIP 16510 |
14.94 |
| 2026-04-12 00:00 |
03:33:07.10 |
-23:23:37.5 |
HIP 16510 |
15.86 |
| 2026-04-12 12:00 |
03:33:11.00 |
-23:23:02.6 |
HIP 16510 |
16.80 |
| 2026-04-13 00:00 |
03:33:14.92 |
-23:22:27.9 |
HIP 16510 |
17.74 |
| 2026-04-13 12:00 |
03:33:18.86 |
-23:21:53.5 |
HIP 16510 |
18.71 |
| 2026-04-14 00:00 |
03:33:22.82 |
-23:21:19.4 |
HIP 16510 |
19.68 |
| 2026-04-14 12:00 |
03:33:26.80 |
-23:20:45.5 |
HIP 16510 |
20.66 |
| 2026-04-15 00:00 |
03:33:30.79 |
-23:20:11.9 |
HIP 16510 |
21.64 |
| 2026-04-15 12:00 |
03:33:34.81 |
-23:19:38.5 |
HIP 16597 |
22.64 |
| 2026-04-16 00:00 |
03:33:38.84 |
-23:19:05.4 |
HIP 16597 |
22.07 |