| 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
$$
M_a = (11.126 + 5.399\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.126 |
| n |
5.399 |
| 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 |
+3.3697 |
-1.131 |
| 2013-12-22 |
2014-03-14 |
+1.6099 |
-2.730 |
| 2014-03-14 |
2014-09-14 |
+3.9594 |
-2.438 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
18:59:29.38 |
-66:22:17.8 |
HIP 93358 |
9.01 |
| 2026-06-01 12:00 |
18:59:21.21 |
-66:22:46.7 |
HIP 93358 |
9.73 |
| 2026-06-02 00:00 |
18:59:12.99 |
-66:23:15.3 |
HIP 93358 |
10.49 |
| 2026-06-02 12:00 |
18:59:04.71 |
-66:23:43.6 |
HIP 93358 |
11.29 |
| 2026-06-03 00:00 |
18:58:56.39 |
-66:24:11.6 |
HIP 93052 |
10.87 |
| 2026-06-03 12:00 |
18:58:48.01 |
-66:24:39.3 |
HIP 93052 |
10.30 |
| 2026-06-04 00:00 |
18:58:39.59 |
-66:25:06.7 |
HIP 93052 |
9.80 |
| 2026-06-04 12:00 |
18:58:31.11 |
-66:25:33.7 |
HIP 93052 |
9.35 |
| 2026-06-05 00:00 |
18:58:22.59 |
-66:26:00.5 |
HIP 93052 |
8.99 |
| 2026-06-05 12:00 |
18:58:14.02 |
-66:26:26.9 |
HIP 93052 |
8.70 |
| 2026-06-06 00:00 |
18:58:05.40 |
-66:26:53.0 |
HIP 93052 |
8.51 |
| 2026-06-06 12:00 |
18:57:56.74 |
-66:27:18.8 |
HIP 93052 |
8.42 |
| 2026-06-07 00:00 |
18:57:48.03 |
-66:27:44.2 |
HIP 93052 |
8.44 |
| 2026-06-07 12:00 |
18:57:39.27 |
-66:28:09.3 |
HIP 93052 |
8.55 |
| 2026-06-08 00:00 |
18:57:30.48 |
-66:28:34.1 |
HIP 93052 |
8.77 |
| 2026-06-08 12:00 |
18:57:21.63 |
-66:28:58.5 |
HIP 93052 |
9.09 |
| 2026-06-09 00:00 |
18:57:12.75 |
-66:29:22.6 |
HIP 93052 |
9.48 |
| 2026-06-09 12:00 |
18:57:03.82 |
-66:29:46.4 |
HIP 93052 |
9.96 |
| 2026-06-10 00:00 |
18:56:54.85 |
-66:30:09.8 |
HIP 93052 |
10.49 |
| 2026-06-10 12:00 |
18:56:45.84 |
-66:30:32.9 |
HIP 93052 |
11.09 |
| 2026-06-11 00:00 |
18:56:36.79 |
-66:30:55.6 |
HIP 93052 |
11.73 |
| 2026-06-11 12:00 |
18:56:27.70 |
-66:31:18.0 |
HIP 93052 |
12.41 |
| 2026-06-12 00:00 |
18:56:18.57 |
-66:31:40.1 |
HIP 93052 |
13.12 |
| 2026-06-12 12:00 |
18:56:09.41 |
-66:32:01.7 |
HIP 93052 |
13.87 |
| 2026-06-13 00:00 |
18:56:00.21 |
-66:32:23.1 |
HIP 93052 |
14.64 |
| 2026-06-13 12:00 |
18:55:50.97 |
-66:32:44.0 |
HIP 93052 |
15.43 |
| 2026-06-14 00:00 |
18:55:41.70 |
-66:33:04.7 |
HIP 93052 |
16.24 |
| 2026-06-14 12:00 |
18:55:32.39 |
-66:33:24.9 |
HIP 93052 |
17.07 |
| 2026-06-15 00:00 |
18:55:23.05 |
-66:33:44.8 |
HIP 93052 |
17.91 |
| 2026-06-15 12:00 |
18:55:13.68 |
-66:34:04.3 |
HIP 93052 |
18.76 |
| 2026-06-16 00:00 |
18:55:04.28 |
-66:34:23.5 |
HIP 93052 |
19.62 |
| 2026-06-16 12:00 |
18:54:54.85 |
-66:34:42.3 |
HIP 93052 |
20.49 |
| 2026-06-17 00:00 |
18:54:45.38 |
-66:35:00.7 |
HIP 93052 |
21.37 |
| 2026-06-17 12:00 |
18:54:35.89 |
-66:35:18.7 |
HIP 93052 |
22.26 |
| 2026-06-18 00:00 |
18:54:26.37 |
-66:35:36.4 |
HIP 93052 |
23.15 |
| 2026-06-18 12:00 |
18:54:16.83 |
-66:35:53.7 |
HIP 93052 |
24.05 |
| 2026-06-19 00:00 |
18:54:07.25 |
-66:36:10.6 |
HIP 93052 |
24.95 |
| 2026-06-19 12:00 |
18:53:57.66 |
-66:36:27.2 |
HIP 93052 |
25.86 |
| 2026-06-20 00:00 |
18:53:48.03 |
-66:36:43.4 |
HIP 93052 |
26.77 |
| 2026-06-20 12:00 |
18:53:38.39 |
-66:36:59.1 |
HIP 93052 |
27.69 |
| 2026-06-21 00:00 |
18:53:28.72 |
-66:37:14.6 |
HIP 93052 |
28.61 |
| 2026-06-21 12:00 |
18:53:19.03 |
-66:37:29.6 |
HIP 93052 |
29.53 |
| 2026-06-22 00:00 |
18:53:09.32 |
-66:37:44.2 |
HIP 93052 |
30.45 |