| Parameter |
Value |
| Designation |
C/1885 X2 (Barnard) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1886-05-03T18:53:20.048640Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:28:53Z |
| Obs used |
76 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1886-02-01.0000000 |
| e |
1.00020016 |
| q (au) |
0.479255 |
| a (au) |
-2394.381815 |
| i (deg) |
84.440812 |
| Ω (om, deg) |
69.909995 |
| ω (w, deg) |
119.624515 |
| M (ma, deg) |
-0.000772 |
Magnitude
Scatter + Global Linear
$$
M_a = (H_0 + n\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
- |
| n |
- |
| gf |
- |
| gb |
- |
| k |
- |
| δ90 |
- |
| 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 |
04:48:19.90 |
-44:26:28.9 |
HIP 22268 |
12.58 |
| 2026-06-01 12:00 |
04:48:20.97 |
-44:26:27.7 |
HIP 22268 |
12.68 |
| 2026-06-02 00:00 |
04:48:22.03 |
-44:26:26.5 |
HIP 22268 |
12.77 |
| 2026-06-02 12:00 |
04:48:23.10 |
-44:26:25.4 |
HIP 22268 |
12.87 |
| 2026-06-03 00:00 |
04:48:24.17 |
-44:26:24.3 |
HIP 22268 |
12.97 |
| 2026-06-03 12:00 |
04:48:25.23 |
-44:26:23.4 |
HIP 22268 |
13.08 |
| 2026-06-04 00:00 |
04:48:26.30 |
-44:26:22.6 |
HIP 22268 |
13.18 |
| 2026-06-04 12:00 |
04:48:27.37 |
-44:26:21.8 |
HIP 22268 |
13.29 |
| 2026-06-05 00:00 |
04:48:28.44 |
-44:26:21.2 |
HIP 22268 |
13.41 |
| 2026-06-05 12:00 |
04:48:29.50 |
-44:26:20.6 |
HIP 22268 |
13.52 |
| 2026-06-06 00:00 |
04:48:30.57 |
-44:26:20.1 |
HIP 22268 |
13.64 |
| 2026-06-06 12:00 |
04:48:31.64 |
-44:26:19.7 |
HIP 22268 |
13.77 |
| 2026-06-07 00:00 |
04:48:32.71 |
-44:26:19.4 |
HIP 22268 |
13.89 |
| 2026-06-07 12:00 |
04:48:33.77 |
-44:26:19.2 |
HIP 22268 |
14.02 |
| 2026-06-08 00:00 |
04:48:34.84 |
-44:26:19.1 |
HIP 22268 |
14.15 |
| 2026-06-08 12:00 |
04:48:35.91 |
-44:26:19.0 |
HIP 22268 |
14.28 |
| 2026-06-09 00:00 |
04:48:36.97 |
-44:26:19.1 |
HIP 22268 |
14.41 |
| 2026-06-09 12:00 |
04:48:38.04 |
-44:26:19.2 |
HIP 22268 |
14.55 |
| 2026-06-10 00:00 |
04:48:39.10 |
-44:26:19.5 |
HIP 22268 |
14.69 |
| 2026-06-10 12:00 |
04:48:40.16 |
-44:26:19.8 |
HIP 22268 |
14.83 |
| 2026-06-11 00:00 |
04:48:41.23 |
-44:26:20.2 |
HIP 22268 |
14.97 |
| 2026-06-11 12:00 |
04:48:42.29 |
-44:26:20.7 |
HIP 22268 |
15.12 |
| 2026-06-12 00:00 |
04:48:43.35 |
-44:26:21.3 |
HIP 22268 |
15.27 |
| 2026-06-12 12:00 |
04:48:44.41 |
-44:26:21.9 |
HIP 22268 |
15.41 |
| 2026-06-13 00:00 |
04:48:45.47 |
-44:26:22.7 |
HIP 22268 |
15.56 |
| 2026-06-13 12:00 |
04:48:46.52 |
-44:26:23.6 |
HIP 22268 |
15.72 |
| 2026-06-14 00:00 |
04:48:47.58 |
-44:26:24.5 |
HIP 22268 |
15.87 |
| 2026-06-14 12:00 |
04:48:48.63 |
-44:26:25.6 |
HIP 22268 |
16.02 |
| 2026-06-15 00:00 |
04:48:49.69 |
-44:26:26.7 |
HIP 22268 |
16.18 |
| 2026-06-15 12:00 |
04:48:50.74 |
-44:26:27.9 |
HIP 22268 |
16.34 |
| 2026-06-16 00:00 |
04:48:51.79 |
-44:26:29.2 |
HIP 22268 |
16.50 |
| 2026-06-16 12:00 |
04:48:52.83 |
-44:26:30.6 |
HIP 22268 |
16.66 |
| 2026-06-17 00:00 |
04:48:53.88 |
-44:26:32.1 |
HIP 22268 |
16.82 |
| 2026-06-17 12:00 |
04:48:54.93 |
-44:26:33.6 |
HIP 22268 |
16.98 |
| 2026-06-18 00:00 |
04:48:55.97 |
-44:26:35.3 |
HIP 22268 |
17.15 |
| 2026-06-18 12:00 |
04:48:57.01 |
-44:26:37.0 |
HIP 22268 |
17.31 |
| 2026-06-19 00:00 |
04:48:58.05 |
-44:26:38.9 |
HIP 22268 |
17.48 |
| 2026-06-19 12:00 |
04:48:59.08 |
-44:26:40.8 |
HIP 22268 |
17.65 |
| 2026-06-20 00:00 |
04:49:00.12 |
-44:26:42.8 |
HIP 22268 |
17.81 |
| 2026-06-20 12:00 |
04:49:01.15 |
-44:26:44.9 |
HIP 22268 |
17.98 |
| 2026-06-21 00:00 |
04:49:02.18 |
-44:26:47.1 |
HIP 22268 |
18.15 |
| 2026-06-21 12:00 |
04:49:03.20 |
-44:26:49.3 |
HIP 22268 |
18.32 |
| 2026-06-22 00:00 |
04:49:04.23 |
-44:26:51.7 |
HIP 22268 |
18.50 |