| Parameter |
Value |
| Designation |
C/2013 N4 (Borisov) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2013-08-21T12:19:51.456000Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:37Z |
| Obs used |
287 |
| NEO |
- |
| M1 |
12.100 |
| K1 |
5.250 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2013-09-15.0000000 |
| e |
0.97480289 |
| q (au) |
1.210405 |
| a (au) |
48.037448 |
| i (deg) |
37.035278 |
| Ω (om, deg) |
322.609954 |
| ω (w, deg) |
142.280706 |
| M (ma, deg) |
0.072486 |
Magnitude
Scatter + Global Linear
$$
M_a = (13.680 + 4.775\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
13.680 |
| n |
4.775 |
| gf |
1.000 |
| gb |
-0.733 |
| 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 |
| 2013-07-08 |
2013-08-18 |
+21.8907 |
-2.670 |
| 2013-08-25 |
2013-12-11 |
-5.2553 |
-1.508 |
| 2013-12-11 |
2014-04-30 |
+14.2425 |
-6.622 |
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 |
18:12:22.55 |
-55:03:55.0 |
HIP 89281 |
8.00 |
| 2026-05-12 12:00 |
18:12:17.26 |
-55:04:17.4 |
HIP 89281 |
8.82 |
| 2026-05-13 00:00 |
18:12:11.92 |
-55:04:39.6 |
HIP 89206 |
9.64 |
| 2026-05-13 12:00 |
18:12:06.54 |
-55:05:01.5 |
HIP 89206 |
10.08 |
| 2026-05-14 00:00 |
18:12:01.11 |
-55:05:23.3 |
HIP 89206 |
10.57 |
| 2026-05-14 12:00 |
18:11:55.64 |
-55:05:44.8 |
HIP 89206 |
11.11 |
| 2026-05-15 00:00 |
18:11:50.12 |
-55:06:06.1 |
HIP 89206 |
11.68 |
| 2026-05-15 12:00 |
18:11:44.56 |
-55:06:27.1 |
HIP 89206 |
12.29 |
| 2026-05-16 00:00 |
18:11:38.95 |
-55:06:47.9 |
HIP 89206 |
12.92 |
| 2026-05-16 12:00 |
18:11:33.30 |
-55:07:08.5 |
HIP 89206 |
13.58 |
| 2026-05-17 00:00 |
18:11:27.61 |
-55:07:28.8 |
HIP 89206 |
14.27 |
| 2026-05-17 12:00 |
18:11:21.88 |
-55:07:48.9 |
HIP 89152 |
14.21 |
| 2026-05-18 00:00 |
18:11:16.11 |
-55:08:08.8 |
HIP 89152 |
14.09 |
| 2026-05-18 12:00 |
18:11:10.29 |
-55:08:28.4 |
HIP 89152 |
14.03 |
| 2026-05-19 00:00 |
18:11:04.44 |
-55:08:47.7 |
HIP 89152 |
14.04 |
| 2026-05-19 12:00 |
18:10:58.54 |
-55:09:06.8 |
HIP 89152 |
14.10 |
| 2026-05-20 00:00 |
18:10:52.61 |
-55:09:25.6 |
HIP 89152 |
14.23 |
| 2026-05-20 12:00 |
18:10:46.63 |
-55:09:44.2 |
HIP 89152 |
14.42 |
| 2026-05-21 00:00 |
18:10:40.62 |
-55:10:02.5 |
HIP 89152 |
14.67 |
| 2026-05-21 12:00 |
18:10:34.57 |
-55:10:20.6 |
HIP 89152 |
14.98 |
| 2026-05-22 00:00 |
18:10:28.49 |
-55:10:38.4 |
HIP 89152 |
15.35 |
| 2026-05-22 12:00 |
18:10:22.37 |
-55:10:55.9 |
HIP 89152 |
15.76 |
| 2026-05-23 00:00 |
18:10:16.21 |
-55:11:13.2 |
HIP 89152 |
16.23 |
| 2026-05-23 12:00 |
18:10:10.01 |
-55:11:30.2 |
HIP 89152 |
16.73 |
| 2026-05-24 00:00 |
18:10:03.79 |
-55:11:47.0 |
HIP 89152 |
17.28 |
| 2026-05-24 12:00 |
18:09:57.52 |
-55:12:03.4 |
HIP 89152 |
17.87 |
| 2026-05-25 00:00 |
18:09:51.23 |
-55:12:19.6 |
HIP 89152 |
18.49 |
| 2026-05-25 12:00 |
18:09:44.90 |
-55:12:35.6 |
HIP 89152 |
19.15 |
| 2026-05-26 00:00 |
18:09:38.53 |
-55:12:51.2 |
HIP 89152 |
19.83 |
| 2026-05-26 12:00 |
18:09:32.14 |
-55:13:06.6 |
HIP 89152 |
20.54 |
| 2026-05-27 00:00 |
18:09:25.71 |
-55:13:21.7 |
HIP 89152 |
21.27 |
| 2026-05-27 12:00 |
18:09:19.26 |
-55:13:36.5 |
HIP 89152 |
22.03 |
| 2026-05-28 00:00 |
18:09:12.77 |
-55:13:51.1 |
HIP 89152 |
22.80 |
| 2026-05-28 12:00 |
18:09:06.25 |
-55:14:05.3 |
HIP 89152 |
23.60 |
| 2026-05-29 00:00 |
18:08:59.71 |
-55:14:19.3 |
HIP 89152 |
24.41 |
| 2026-05-29 12:00 |
18:08:53.13 |
-55:14:33.0 |
HIP 89152 |
25.24 |
| 2026-05-30 00:00 |
18:08:46.53 |
-55:14:46.4 |
HIP 88642 |
26.02 |
| 2026-05-30 12:00 |
18:08:39.90 |
-55:14:59.6 |
HIP 88642 |
25.18 |
| 2026-05-31 00:00 |
18:08:33.24 |
-55:15:12.4 |
HIP 88642 |
24.34 |
| 2026-05-31 12:00 |
18:08:26.55 |
-55:15:25.0 |
HIP 88642 |
23.51 |
| 2026-06-01 00:00 |
18:08:19.84 |
-55:15:37.2 |
HIP 88642 |
22.68 |
| 2026-06-01 12:00 |
18:08:13.10 |
-55:15:49.2 |
HIP 88642 |
21.86 |
| 2026-06-02 00:00 |
18:08:06.34 |
-55:16:00.9 |
HIP 88642 |
21.05 |