| Parameter |
Value |
| Designation |
C/2015 D4 (Borisov) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2014-10-28T05:41:47.852160Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:07Z |
| Obs used |
51 |
| NEO |
- |
| M1 |
9.200 |
| K1 |
16.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2015-03-30.0000000 |
| e |
0.98906756 |
| q (au) |
0.861677 |
| a (au) |
78.818308 |
| i (deg) |
77.301723 |
| Ω (om, deg) |
305.810298 |
| ω (w, deg) |
314.694165 |
| M (ma, deg) |
0.215169 |
Magnitude
Scatter + Global Linear
$$
M_a = (9.234 + 5.834\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.234 |
| n |
5.834 |
| gf |
1.000 |
| gb |
-0.503 |
| k |
1.000 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
09:05:26.65 |
+80:47:47.8 |
HIP 45097 |
13.95 |
| 2026-07-29 12:00 |
09:05:51.52 |
+80:47:29.6 |
HIP 45097 |
13.02 |
| 2026-07-30 00:00 |
09:06:16.40 |
+80:47:11.8 |
HIP 45097 |
12.10 |
| 2026-07-30 12:00 |
09:06:41.28 |
+80:46:54.4 |
HIP 45097 |
11.21 |
| 2026-07-31 00:00 |
09:07:06.16 |
+80:46:37.3 |
HIP 45097 |
10.33 |
| 2026-07-31 12:00 |
09:07:31.04 |
+80:46:20.6 |
HIP 45097 |
9.49 |
| 2026-08-01 00:00 |
09:07:55.92 |
+80:46:04.2 |
HIP 45097 |
8.68 |
| 2026-08-01 12:00 |
09:08:20.80 |
+80:45:48.2 |
HIP 45097 |
7.92 |
| 2026-08-02 00:00 |
09:08:45.68 |
+80:45:32.6 |
HIP 45097 |
7.22 |
| 2026-08-02 12:00 |
09:09:10.55 |
+80:45:17.3 |
HIP 45097 |
6.61 |
| 2026-08-03 00:00 |
09:09:35.42 |
+80:45:02.4 |
HIP 45097 |
6.10 |
| 2026-08-03 12:00 |
09:10:00.29 |
+80:44:47.9 |
HIP 45097 |
5.73 |
| 2026-08-04 00:00 |
09:10:25.15 |
+80:44:33.8 |
HIP 45097 |
5.51 |
| 2026-08-04 12:00 |
09:10:50.01 |
+80:44:20.0 |
HIP 45097 |
5.48 |
| 2026-08-05 00:00 |
09:11:14.86 |
+80:44:06.6 |
HIP 45097 |
5.63 |
| 2026-08-05 12:00 |
09:11:39.70 |
+80:43:53.5 |
HIP 45097 |
5.94 |
| 2026-08-06 00:00 |
09:12:04.54 |
+80:43:40.9 |
HIP 45097 |
6.40 |
| 2026-08-06 12:00 |
09:12:29.37 |
+80:43:28.6 |
HIP 45097 |
6.97 |
| 2026-08-07 00:00 |
09:12:54.18 |
+80:43:16.7 |
HIP 45097 |
7.63 |
| 2026-08-07 12:00 |
09:13:18.99 |
+80:43:05.1 |
HIP 45097 |
8.36 |
| 2026-08-08 00:00 |
09:13:43.79 |
+80:42:54.0 |
HIP 45097 |
9.13 |
| 2026-08-08 12:00 |
09:14:08.58 |
+80:42:43.2 |
HIP 45097 |
9.95 |
| 2026-08-09 00:00 |
09:14:33.35 |
+80:42:32.8 |
HIP 45097 |
10.79 |
| 2026-08-09 12:00 |
09:14:58.11 |
+80:42:22.8 |
HIP 45097 |
11.66 |
| 2026-08-10 00:00 |
09:15:22.86 |
+80:42:13.1 |
HIP 45097 |
12.54 |
| 2026-08-10 12:00 |
09:15:47.59 |
+80:42:03.9 |
HIP 45097 |
13.43 |
| 2026-08-11 00:00 |
09:16:12.31 |
+80:41:55.0 |
HIP 45097 |
14.34 |
| 2026-08-11 12:00 |
09:16:37.00 |
+80:41:46.5 |
HIP 45097 |
15.26 |
| 2026-08-12 00:00 |
09:17:01.69 |
+80:41:38.4 |
HIP 45097 |
16.18 |
| 2026-08-12 12:00 |
09:17:26.35 |
+80:41:30.7 |
HIP 45097 |
17.10 |
| 2026-08-13 00:00 |
09:17:50.99 |
+80:41:23.4 |
HIP 45097 |
18.04 |
| 2026-08-13 12:00 |
09:18:15.61 |
+80:41:16.4 |
HIP 45097 |
18.97 |
| 2026-08-14 00:00 |
09:18:40.22 |
+80:41:09.9 |
HIP 45097 |
19.91 |
| 2026-08-14 12:00 |
09:19:04.79 |
+80:41:03.7 |
HIP 46330 |
20.56 |
| 2026-08-15 00:00 |
09:19:29.35 |
+80:40:58.0 |
HIP 46330 |
19.61 |
| 2026-08-15 12:00 |
09:19:53.88 |
+80:40:52.6 |
HIP 46330 |
18.67 |
| 2026-08-16 00:00 |
09:20:18.39 |
+80:40:47.6 |
HIP 46330 |
17.74 |
| 2026-08-16 12:00 |
09:20:42.87 |
+80:40:43.0 |
HIP 46330 |
16.82 |
| 2026-08-17 00:00 |
09:21:07.32 |
+80:40:38.8 |
HIP 46330 |
15.92 |
| 2026-08-17 12:00 |
09:21:31.75 |
+80:40:35.0 |
HIP 46330 |
15.03 |
| 2026-08-18 00:00 |
09:21:56.15 |
+80:40:31.5 |
HIP 46330 |
14.16 |
| 2026-08-18 12:00 |
09:22:20.52 |
+80:40:28.5 |
HIP 46330 |
13.32 |
| 2026-08-19 00:00 |
09:22:44.86 |
+80:40:25.9 |
HIP 46330 |
12.50 |