| 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) |
| 2026-06-01 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 |
| 2026-06-02 12:00 |
18:07:59.55 |
-55:16:12.2 |
HIP 88642 |
20.26 |
| 2026-06-03 00:00 |
18:07:52.74 |
-55:16:23.3 |
HIP 88659 |
19.37 |
| 2026-06-03 12:00 |
18:07:45.91 |
-55:16:34.1 |
HIP 88659 |
18.49 |
| 2026-06-04 00:00 |
18:07:39.05 |
-55:16:44.6 |
HIP 88659 |
17.61 |
| 2026-06-04 12:00 |
18:07:32.17 |
-55:16:54.8 |
HIP 88659 |
16.75 |
| 2026-06-05 00:00 |
18:07:25.27 |
-55:17:04.7 |
HIP 88659 |
15.91 |
| 2026-06-05 12:00 |
18:07:18.35 |
-55:17:14.3 |
HIP 88659 |
15.08 |
| 2026-06-06 00:00 |
18:07:11.41 |
-55:17:23.6 |
HIP 88659 |
14.28 |
| 2026-06-06 12:00 |
18:07:04.45 |
-55:17:32.6 |
HIP 88659 |
13.51 |
| 2026-06-07 00:00 |
18:06:57.47 |
-55:17:41.3 |
HIP 88659 |
12.78 |
| 2026-06-07 12:00 |
18:06:50.47 |
-55:17:49.6 |
HIP 88659 |
12.08 |
| 2026-06-08 00:00 |
18:06:43.45 |
-55:17:57.7 |
HIP 88659 |
11.43 |
| 2026-06-08 12:00 |
18:06:36.41 |
-55:18:05.5 |
HIP 88659 |
10.84 |
| 2026-06-09 00:00 |
18:06:29.36 |
-55:18:12.9 |
HIP 88659 |
10.32 |
| 2026-06-09 12:00 |
18:06:22.29 |
-55:18:20.1 |
HIP 88659 |
9.88 |
| 2026-06-10 00:00 |
18:06:15.21 |
-55:18:26.9 |
HIP 88659 |
9.54 |
| 2026-06-10 12:00 |
18:06:08.11 |
-55:18:33.5 |
HIP 88659 |
9.29 |
| 2026-06-11 00:00 |
18:06:00.99 |
-55:18:39.7 |
HIP 88659 |
9.16 |
| 2026-06-11 12:00 |
18:05:53.86 |
-55:18:45.6 |
HIP 88659 |
9.14 |
| 2026-06-12 00:00 |
18:05:46.72 |
-55:18:51.2 |
HIP 88659 |
9.25 |
| 2026-06-12 12:00 |
18:05:39.57 |
-55:18:56.5 |
HIP 88659 |
9.46 |
| 2026-06-13 00:00 |
18:05:32.40 |
-55:19:01.4 |
HIP 88659 |
9.79 |
| 2026-06-13 12:00 |
18:05:25.22 |
-55:19:06.1 |
HIP 88659 |
10.21 |
| 2026-06-14 00:00 |
18:05:18.04 |
-55:19:10.4 |
HIP 88659 |
10.72 |
| 2026-06-14 12:00 |
18:05:10.84 |
-55:19:14.4 |
HIP 88659 |
11.30 |
| 2026-06-15 00:00 |
18:05:03.63 |
-55:19:18.1 |
HIP 88659 |
11.95 |
| 2026-06-15 12:00 |
18:04:56.42 |
-55:19:21.5 |
HIP 88659 |
12.65 |
| 2026-06-16 00:00 |
18:04:49.19 |
-55:19:24.5 |
HIP 88659 |
13.40 |
| 2026-06-16 12:00 |
18:04:41.96 |
-55:19:27.3 |
HIP 88659 |
14.19 |
| 2026-06-17 00:00 |
18:04:34.72 |
-55:19:29.7 |
HIP 88659 |
15.01 |
| 2026-06-17 12:00 |
18:04:27.48 |
-55:19:31.8 |
HIP 88659 |
15.85 |
| 2026-06-18 00:00 |
18:04:20.23 |
-55:19:33.6 |
HIP 88659 |
16.72 |
| 2026-06-18 12:00 |
18:04:12.98 |
-55:19:35.0 |
HIP 88659 |
17.62 |
| 2026-06-19 00:00 |
18:04:05.73 |
-55:19:36.2 |
HIP 88659 |
18.52 |
| 2026-06-19 12:00 |
18:03:58.47 |
-55:19:37.0 |
HIP 88659 |
19.45 |
| 2026-06-20 00:00 |
18:03:51.21 |
-55:19:37.5 |
HIP 88659 |
20.38 |
| 2026-06-20 12:00 |
18:03:43.94 |
-55:19:37.7 |
HIP 88659 |
21.33 |
| 2026-06-21 00:00 |
18:03:36.68 |
-55:19:37.5 |
HIP 88659 |
22.29 |
| 2026-06-21 12:00 |
18:03:29.42 |
-55:19:37.1 |
HIP 88659 |
23.25 |
| 2026-06-22 00:00 |
18:03:22.15 |
-55:19:36.3 |
HIP 88659 |
24.22 |