| 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) |
| 2026-06-01 00:00 |
08:21:36.49 |
+81:59:10.9 |
HIP 40288 |
21.79 |
| 2026-06-01 12:00 |
08:21:54.59 |
+81:58:18.4 |
HIP 40288 |
21.77 |
| 2026-06-02 00:00 |
08:22:12.81 |
+81:57:26.1 |
HIP 40288 |
21.82 |
| 2026-06-02 12:00 |
08:22:31.16 |
+81:56:34.0 |
HIP 40288 |
21.93 |
| 2026-06-03 00:00 |
08:22:49.64 |
+81:55:42.2 |
HIP 41392 |
21.26 |
| 2026-06-03 12:00 |
08:23:08.24 |
+81:54:50.5 |
HIP 41392 |
20.21 |
| 2026-06-04 00:00 |
08:23:26.96 |
+81:53:59.1 |
HIP 41392 |
19.17 |
| 2026-06-04 12:00 |
08:23:45.80 |
+81:53:07.9 |
HIP 41392 |
18.13 |
| 2026-06-05 00:00 |
08:24:04.77 |
+81:52:16.9 |
HIP 41392 |
17.11 |
| 2026-06-05 12:00 |
08:24:23.85 |
+81:51:26.2 |
HIP 41392 |
16.09 |
| 2026-06-06 00:00 |
08:24:43.05 |
+81:50:35.6 |
HIP 41392 |
15.08 |
| 2026-06-06 12:00 |
08:25:02.36 |
+81:49:45.3 |
HIP 41392 |
14.09 |
| 2026-06-07 00:00 |
08:25:21.79 |
+81:48:55.2 |
HIP 41392 |
13.11 |
| 2026-06-07 12:00 |
08:25:41.33 |
+81:48:05.4 |
HIP 41392 |
12.16 |
| 2026-06-08 00:00 |
08:26:00.99 |
+81:47:15.8 |
HIP 41392 |
11.24 |
| 2026-06-08 12:00 |
08:26:20.75 |
+81:46:26.4 |
HIP 41392 |
10.35 |
| 2026-06-09 00:00 |
08:26:40.62 |
+81:45:37.3 |
HIP 41392 |
9.50 |
| 2026-06-09 12:00 |
08:27:00.60 |
+81:44:48.3 |
HIP 41392 |
8.72 |
| 2026-06-10 00:00 |
08:27:20.69 |
+81:43:59.7 |
HIP 41392 |
8.01 |
| 2026-06-10 12:00 |
08:27:40.88 |
+81:43:11.3 |
HIP 41392 |
7.40 |
| 2026-06-11 00:00 |
08:28:01.17 |
+81:42:23.1 |
HIP 41392 |
6.91 |
| 2026-06-11 12:00 |
08:28:21.57 |
+81:41:35.1 |
HIP 41392 |
6.58 |
| 2026-06-12 00:00 |
08:28:42.07 |
+81:40:47.4 |
HIP 41392 |
6.43 |
| 2026-06-12 12:00 |
08:29:02.67 |
+81:40:00.0 |
HIP 41392 |
6.46 |
| 2026-06-13 00:00 |
08:29:23.36 |
+81:39:12.8 |
HIP 41392 |
6.68 |
| 2026-06-13 12:00 |
08:29:44.16 |
+81:38:25.9 |
HIP 41392 |
7.07 |
| 2026-06-14 00:00 |
08:30:05.04 |
+81:37:39.2 |
HIP 41392 |
7.61 |
| 2026-06-14 12:00 |
08:30:26.03 |
+81:36:52.7 |
HIP 41392 |
8.26 |
| 2026-06-15 00:00 |
08:30:47.10 |
+81:36:06.6 |
HIP 41392 |
9.00 |
| 2026-06-15 12:00 |
08:31:08.27 |
+81:35:20.7 |
HIP 41392 |
9.81 |
| 2026-06-16 00:00 |
08:31:29.52 |
+81:34:35.0 |
HIP 41392 |
10.67 |
| 2026-06-16 12:00 |
08:31:50.87 |
+81:33:49.6 |
HIP 41392 |
11.58 |
| 2026-06-17 00:00 |
08:32:12.30 |
+81:33:04.5 |
HIP 41392 |
12.52 |
| 2026-06-17 12:00 |
08:32:33.81 |
+81:32:19.7 |
HIP 41392 |
13.48 |
| 2026-06-18 00:00 |
08:32:55.41 |
+81:31:35.1 |
HIP 41392 |
14.47 |
| 2026-06-18 12:00 |
08:33:17.09 |
+81:30:50.8 |
HIP 41392 |
15.47 |
| 2026-06-19 00:00 |
08:33:38.86 |
+81:30:06.7 |
HIP 41392 |
16.49 |
| 2026-06-19 12:00 |
08:34:00.70 |
+81:29:22.9 |
HIP 41392 |
17.52 |
| 2026-06-20 00:00 |
08:34:22.62 |
+81:28:39.5 |
HIP 41392 |
18.56 |
| 2026-06-20 12:00 |
08:34:44.62 |
+81:27:56.2 |
HIP 41392 |
19.60 |
| 2026-06-21 00:00 |
08:35:06.69 |
+81:27:13.3 |
HIP 41392 |
20.65 |
| 2026-06-21 12:00 |
08:35:28.84 |
+81:26:30.6 |
HIP 41392 |
21.71 |
| 2026-06-22 00:00 |
08:35:51.06 |
+81:25:48.2 |
HIP 41392 |
22.77 |