| 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 |
+6.3519 |
-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) |
| 2026-09-20 00:00 |
03:47:06.37 |
-24:33:06.9 |
HIP 17600 |
15.49 |
| 2026-09-20 12:00 |
03:47:04.39 |
-24:33:48.2 |
HIP 17600 |
15.58 |
| 2026-09-21 00:00 |
03:47:02.37 |
-24:34:29.5 |
HIP 17600 |
15.72 |
| 2026-09-21 12:00 |
03:47:00.32 |
-24:35:10.7 |
HIP 17600 |
15.89 |
| 2026-09-22 00:00 |
03:46:58.23 |
-24:35:51.8 |
HIP 17638 |
15.78 |
| 2026-09-22 12:00 |
03:46:56.11 |
-24:36:32.8 |
HIP 17638 |
15.02 |
| 2026-09-23 00:00 |
03:46:53.96 |
-24:37:13.6 |
HIP 17638 |
14.27 |
| 2026-09-23 12:00 |
03:46:51.77 |
-24:37:54.3 |
HIP 17638 |
13.53 |
| 2026-09-24 00:00 |
03:46:49.54 |
-24:38:34.9 |
HIP 17638 |
12.81 |
| 2026-09-24 12:00 |
03:46:47.28 |
-24:39:15.4 |
HIP 17638 |
12.10 |
| 2026-09-25 00:00 |
03:46:44.99 |
-24:39:55.8 |
HIP 17638 |
11.42 |
| 2026-09-25 12:00 |
03:46:42.67 |
-24:40:36.0 |
HIP 17638 |
10.76 |
| 2026-09-26 00:00 |
03:46:40.31 |
-24:41:16.1 |
HIP 17638 |
10.13 |
| 2026-09-26 12:00 |
03:46:37.92 |
-24:41:56.0 |
HIP 17638 |
9.54 |
| 2026-09-27 00:00 |
03:46:35.50 |
-24:42:35.9 |
HIP 17638 |
9.00 |
| 2026-09-27 12:00 |
03:46:33.04 |
-24:43:15.5 |
HIP 17638 |
8.52 |
| 2026-09-28 00:00 |
03:46:30.55 |
-24:43:55.0 |
HIP 17638 |
8.11 |
| 2026-09-28 12:00 |
03:46:28.03 |
-24:44:34.4 |
HIP 17638 |
7.78 |
| 2026-09-29 00:00 |
03:46:25.47 |
-24:45:13.6 |
HIP 17638 |
7.54 |
| 2026-09-29 12:00 |
03:46:22.89 |
-24:45:52.7 |
HIP 17638 |
7.40 |
| 2026-09-30 00:00 |
03:46:20.27 |
-24:46:31.6 |
HIP 17638 |
7.37 |
| 2026-09-30 12:00 |
03:46:17.62 |
-24:47:10.3 |
HIP 17638 |
7.46 |
| 2026-10-01 00:00 |
03:46:14.94 |
-24:47:48.9 |
HIP 17638 |
7.65 |
| 2026-10-01 12:00 |
03:46:12.22 |
-24:48:27.3 |
HIP 17638 |
7.95 |
| 2026-10-02 00:00 |
03:46:09.48 |
-24:49:05.5 |
HIP 17638 |
8.33 |
| 2026-10-02 12:00 |
03:46:06.70 |
-24:49:43.6 |
HIP 17638 |
8.80 |
| 2026-10-03 00:00 |
03:46:03.90 |
-24:50:21.5 |
HIP 17638 |
9.34 |
| 2026-10-03 12:00 |
03:46:01.06 |
-24:50:59.2 |
HIP 17638 |
9.94 |
| 2026-10-04 00:00 |
03:45:58.19 |
-24:51:36.7 |
HIP 17638 |
10.59 |
| 2026-10-04 12:00 |
03:45:55.30 |
-24:52:14.0 |
HIP 17638 |
11.27 |
| 2026-10-05 00:00 |
03:45:52.37 |
-24:52:51.1 |
HIP 17638 |
12.00 |
| 2026-10-05 12:00 |
03:45:49.41 |
-24:53:28.0 |
HIP 17638 |
12.75 |
| 2026-10-06 00:00 |
03:45:46.42 |
-24:54:04.7 |
HIP 17638 |
13.53 |
| 2026-10-06 12:00 |
03:45:43.40 |
-24:54:41.2 |
HIP 17638 |
14.33 |
| 2026-10-07 00:00 |
03:45:40.36 |
-24:55:17.5 |
HIP 17638 |
15.15 |
| 2026-10-07 12:00 |
03:45:37.28 |
-24:55:53.6 |
HIP 17638 |
15.98 |
| 2026-10-08 00:00 |
03:45:34.18 |
-24:56:29.5 |
HIP 17638 |
16.83 |
| 2026-10-08 12:00 |
03:45:31.04 |
-24:57:05.2 |
HIP 17638 |
17.69 |
| 2026-10-09 00:00 |
03:45:27.88 |
-24:57:40.6 |
HIP 17463 |
17.52 |
| 2026-10-09 12:00 |
03:45:24.69 |
-24:58:15.8 |
HIP 17463 |
16.60 |
| 2026-10-10 00:00 |
03:45:21.48 |
-24:58:50.8 |
HIP 17463 |
15.67 |
| 2026-10-10 12:00 |
03:45:18.23 |
-24:59:25.6 |
HIP 17463 |
14.74 |
| 2026-10-11 00:00 |
03:45:14.96 |
-25:00:00.1 |
HIP 17463 |
13.82 |