| Parameter |
Value |
| Designation |
C/2014 UN271 (Bernardinelli-Bernstein) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2031-01-25T14:38:51.518400Z |
| Orbit solution date (soln_date, UTC) |
2026-09-08T09:12:16Z |
| Obs used |
2298 |
| NEO |
- |
| M1 |
5.600 |
| K1 |
4.250 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2021-12-29.0000000 |
| e |
0.99925932 |
| q (au) |
10.937400 |
| a (au) |
14766.649086 |
| i (deg) |
95.436579 |
| Ω (om, deg) |
189.911612 |
| ω (w, deg) |
326.337772 |
| M (ma, deg) |
359.998179 |
Magnitude
Scatter + Global Linear
$$
M_a = (-5.000 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
-5.000 |
| n |
6.000 |
| gf |
0.800 |
| gb |
-0.745 |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
07:28:25.32 |
-71:02:22.3 |
HIP 35882 |
27.50 |
| 2026-09-20 12:00 |
07:28:44.67 |
-71:04:11.7 |
HIP 35882 |
29.84 |
| 2026-09-21 00:00 |
07:29:03.88 |
-71:06:01.4 |
HIP 35946 |
30.85 |
| 2026-09-21 12:00 |
07:29:22.93 |
-71:07:51.5 |
HIP 35946 |
30.67 |
| 2026-09-22 00:00 |
07:29:41.84 |
-71:09:41.9 |
HIP 35946 |
30.65 |
| 2026-09-22 12:00 |
07:30:00.60 |
-71:11:32.5 |
HIP 35946 |
30.81 |
| 2026-09-23 00:00 |
07:30:19.21 |
-71:13:23.5 |
HIP 35946 |
31.13 |
| 2026-09-23 12:00 |
07:30:37.67 |
-71:15:14.7 |
HIP 35946 |
31.60 |
| 2026-09-24 00:00 |
07:30:55.98 |
-71:17:06.3 |
HIP 35946 |
32.23 |
| 2026-09-24 12:00 |
07:31:14.13 |
-71:18:58.1 |
HIP 35946 |
33.00 |
| 2026-09-25 00:00 |
07:31:32.13 |
-71:20:50.3 |
HIP 35946 |
33.90 |
| 2026-09-25 12:00 |
07:31:49.98 |
-71:22:42.7 |
HIP 35946 |
34.91 |
| 2026-09-26 00:00 |
07:32:07.67 |
-71:24:35.3 |
HIP 36610 |
35.74 |
| 2026-09-26 12:00 |
07:32:25.20 |
-71:26:28.2 |
HIP 36610 |
33.96 |
| 2026-09-27 00:00 |
07:32:42.57 |
-71:28:21.4 |
HIP 36610 |
32.25 |
| 2026-09-27 12:00 |
07:32:59.78 |
-71:30:14.9 |
HIP 36610 |
30.61 |
| 2026-09-28 00:00 |
07:33:16.83 |
-71:32:08.6 |
HIP 36610 |
29.06 |
| 2026-09-28 12:00 |
07:33:33.72 |
-71:34:02.5 |
HIP 36610 |
27.61 |
| 2026-09-29 00:00 |
07:33:50.45 |
-71:35:56.7 |
HIP 36610 |
26.27 |
| 2026-09-29 12:00 |
07:34:07.01 |
-71:37:51.1 |
HIP 36610 |
25.06 |
| 2026-09-30 00:00 |
07:34:23.40 |
-71:39:45.8 |
HIP 36610 |
23.99 |
| 2026-09-30 12:00 |
07:34:39.63 |
-71:41:40.7 |
HIP 36610 |
23.10 |
| 2026-10-01 00:00 |
07:34:55.69 |
-71:43:35.8 |
HIP 36610 |
22.39 |
| 2026-10-01 12:00 |
07:35:11.58 |
-71:45:31.1 |
HIP 36610 |
21.88 |
| 2026-10-02 00:00 |
07:35:27.29 |
-71:47:26.7 |
HIP 36610 |
21.59 |
| 2026-10-02 12:00 |
07:35:42.84 |
-71:49:22.4 |
HIP 36610 |
21.52 |
| 2026-10-03 00:00 |
07:35:58.21 |
-71:51:18.3 |
HIP 36610 |
21.68 |
| 2026-10-03 12:00 |
07:36:13.40 |
-71:53:14.5 |
HIP 36610 |
22.05 |
| 2026-10-04 00:00 |
07:36:28.42 |
-71:55:10.8 |
HIP 37403 |
22.24 |
| 2026-10-04 12:00 |
07:36:43.26 |
-71:57:07.3 |
HIP 37403 |
22.11 |
| 2026-10-05 00:00 |
07:36:57.92 |
-71:59:04.0 |
HIP 37403 |
22.23 |
| 2026-10-05 12:00 |
07:37:12.40 |
-72:01:00.8 |
HIP 37403 |
22.60 |
| 2026-10-06 00:00 |
07:37:26.70 |
-72:02:57.9 |
HIP 37403 |
23.18 |
| 2026-10-06 12:00 |
07:37:40.81 |
-72:04:55.0 |
HIP 37403 |
23.98 |
| 2026-10-07 00:00 |
07:37:54.73 |
-72:06:52.4 |
HIP 37403 |
24.97 |
| 2026-10-07 12:00 |
07:38:08.47 |
-72:08:49.8 |
HIP 37403 |
26.12 |
| 2026-10-08 00:00 |
07:38:22.02 |
-72:10:47.4 |
HIP 37331 |
25.01 |
| 2026-10-08 12:00 |
07:38:35.39 |
-72:12:45.2 |
HIP 37331 |
22.85 |
| 2026-10-09 00:00 |
07:38:48.56 |
-72:14:43.0 |
HIP 37331 |
20.71 |
| 2026-10-09 12:00 |
07:39:01.53 |
-72:16:41.0 |
HIP 37331 |
18.58 |
| 2026-10-10 00:00 |
07:39:14.32 |
-72:18:39.1 |
HIP 37331 |
16.48 |
| 2026-10-10 12:00 |
07:39:26.90 |
-72:20:37.3 |
HIP 37331 |
14.40 |
| 2026-10-11 00:00 |
07:39:39.30 |
-72:22:35.6 |
HIP 37331 |
12.35 |