C/2013 R1 (Lovejoy)
| Parameter |
Value |
| Designation |
C/2013 R1 (Lovejoy) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2013-12-22T17:35:41.714880Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:40Z |
| Obs used |
3894 |
| NEO |
- |
| M1 |
11.500 |
| K1 |
7.250 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2013-12-29.0000000 |
| e |
0.99842519 |
| q (au) |
0.811826 |
| a (au) |
515.505940 |
| i (deg) |
64.040953 |
| Ω (om, deg) |
70.711175 |
| ω (w, deg) |
67.166449 |
| M (ma, deg) |
0.000528 |
Magnitude
Scatter + Global Linear
$$
M_a = (11.135 + 5.390\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.135 |
| n |
5.390 |
| gf |
1.000 |
| gb |
-0.758 |
| k |
0.800 |
| 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 |
| 2013-09-07 |
2013-12-22 |
+3.3799 |
-1.134 |
| 2013-12-22 |
2014-03-14 |
+1.6314 |
-2.739 |
| 2014-03-14 |
2014-09-14 |
+3.9868 |
-2.448 |
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 |
18:57:23.78 |
-63:58:51.9 |
HIP 93151 |
7.18 |
| 2026-02-03 12:00 |
18:57:32.05 |
-63:59:10.6 |
HIP 93151 |
6.24 |
| 2026-02-04 00:00 |
18:57:40.29 |
-63:59:29.7 |
HIP 93151 |
5.30 |
| 2026-02-04 12:00 |
18:57:48.48 |
-63:59:49.0 |
HIP 93151 |
4.38 |
| 2026-02-05 00:00 |
18:57:56.63 |
-64:00:08.7 |
HIP 93151 |
3.48 |
| 2026-02-05 12:00 |
18:58:04.75 |
-64:00:28.6 |
HIP 93151 |
2.62 |
| 2026-02-06 00:00 |
18:58:12.83 |
-64:00:48.8 |
HIP 93151 |
1.85 |
| 2026-02-06 12:00 |
18:58:20.86 |
-64:01:09.3 |
HIP 93151 |
1.35 |
| 2026-02-07 00:00 |
18:58:28.86 |
-64:01:30.1 |
HIP 93151 |
1.42 |
| 2026-02-07 12:00 |
18:58:36.82 |
-64:01:51.2 |
HIP 93151 |
2.00 |
| 2026-02-08 00:00 |
18:58:44.73 |
-64:02:12.6 |
HIP 93151 |
2.79 |
| 2026-02-08 12:00 |
18:58:52.60 |
-64:02:34.3 |
HIP 93151 |
3.64 |
| 2026-02-09 00:00 |
18:59:00.43 |
-64:02:56.3 |
HIP 93151 |
4.53 |
| 2026-02-09 12:00 |
18:59:08.21 |
-64:03:18.5 |
HIP 93151 |
5.43 |
| 2026-02-10 00:00 |
18:59:15.96 |
-64:03:41.1 |
HIP 93151 |
6.34 |
| 2026-02-10 12:00 |
18:59:23.65 |
-64:04:03.9 |
HIP 93151 |
7.25 |
| 2026-02-11 00:00 |
18:59:31.31 |
-64:04:27.0 |
HIP 93151 |
8.16 |
| 2026-02-11 12:00 |
18:59:38.91 |
-64:04:50.4 |
HIP 93151 |
9.07 |
| 2026-02-12 00:00 |
18:59:46.48 |
-64:05:14.1 |
HIP 93151 |
9.98 |
| 2026-02-12 12:00 |
18:59:53.99 |
-64:05:38.0 |
HIP 93151 |
10.89 |
| 2026-02-13 00:00 |
19:00:01.46 |
-64:06:02.2 |
HIP 93151 |
11.80 |
| 2026-02-13 12:00 |
19:00:08.88 |
-64:06:26.8 |
HIP 93151 |
12.71 |
| 2026-02-14 00:00 |
19:00:16.25 |
-64:06:51.6 |
HIP 93151 |
13.61 |
| 2026-02-14 12:00 |
19:00:23.58 |
-64:07:16.6 |
HIP 93151 |
14.51 |
| 2026-02-15 00:00 |
19:00:30.85 |
-64:07:42.0 |
HIP 93151 |
15.41 |
| 2026-02-15 12:00 |
19:00:38.08 |
-64:08:07.6 |
HIP 93151 |
16.31 |
| 2026-02-16 00:00 |
19:00:45.25 |
-64:08:33.5 |
HIP 93151 |
17.20 |
| 2026-02-16 12:00 |
19:00:52.38 |
-64:08:59.7 |
HIP 93151 |
18.09 |
| 2026-02-17 00:00 |
19:00:59.45 |
-64:09:26.1 |
HIP 93151 |
18.98 |
| 2026-02-17 12:00 |
19:01:06.47 |
-64:09:52.8 |
HIP 93151 |
19.86 |
| 2026-02-18 00:00 |
19:01:13.44 |
-64:10:19.8 |
HIP 93151 |
20.75 |
| 2026-02-18 12:00 |
19:01:20.36 |
-64:10:47.0 |
HIP 93151 |
21.63 |
| 2026-02-19 00:00 |
19:01:27.22 |
-64:11:14.5 |
HIP 93151 |
22.50 |
| 2026-02-19 12:00 |
19:01:34.03 |
-64:11:42.3 |
HIP 93151 |
23.37 |
| 2026-02-20 00:00 |
19:01:40.79 |
-64:12:10.3 |
HIP 93151 |
24.24 |
| 2026-02-20 12:00 |
19:01:47.49 |
-64:12:38.6 |
HIP 93151 |
25.11 |
| 2026-02-21 00:00 |
19:01:54.14 |
-64:13:07.2 |
HIP 93151 |
25.97 |
| 2026-02-21 12:00 |
19:02:00.73 |
-64:13:36.0 |
HIP 93151 |
26.84 |
| 2026-02-22 00:00 |
19:02:07.26 |
-64:14:05.1 |
HIP 93151 |
27.69 |
| 2026-02-22 12:00 |
19:02:13.74 |
-64:14:34.4 |
HIP 93151 |
28.55 |
| 2026-02-23 00:00 |
19:02:20.16 |
-64:15:03.9 |
HIP 93151 |
29.40 |
| 2026-02-23 12:00 |
19:02:26.52 |
-64:15:33.8 |
HIP 93151 |
30.24 |
| 2026-02-24 00:00 |
19:02:32.83 |
-64:16:03.8 |
HIP 93637 |
30.73 |