C/1885 X2 (Barnard)
| 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) |
| 2026-02-03 00:00 |
04:46:37.94 |
-44:58:58.8 |
HIP 22318 |
19.11 |
| 2026-02-03 12:00 |
04:46:37.39 |
-44:58:49.4 |
HIP 22318 |
19.22 |
| 2026-02-04 00:00 |
04:46:36.86 |
-44:58:40.0 |
HIP 22318 |
19.33 |
| 2026-02-04 12:00 |
04:46:36.32 |
-44:58:30.5 |
HIP 22318 |
19.44 |
| 2026-02-05 00:00 |
04:46:35.80 |
-44:58:21.0 |
HIP 22318 |
19.55 |
| 2026-02-05 12:00 |
04:46:35.29 |
-44:58:11.5 |
HIP 22318 |
19.66 |
| 2026-02-06 00:00 |
04:46:34.78 |
-44:58:01.9 |
HIP 22318 |
19.77 |
| 2026-02-06 12:00 |
04:46:34.29 |
-44:57:52.2 |
HIP 22318 |
19.88 |
| 2026-02-07 00:00 |
04:46:33.80 |
-44:57:42.5 |
HIP 22318 |
19.99 |
| 2026-02-07 12:00 |
04:46:33.32 |
-44:57:32.8 |
HIP 22318 |
20.10 |
| 2026-02-08 00:00 |
04:46:32.85 |
-44:57:23.0 |
HIP 22318 |
20.21 |
| 2026-02-08 12:00 |
04:46:32.39 |
-44:57:13.1 |
HIP 22318 |
20.31 |
| 2026-02-09 00:00 |
04:46:31.94 |
-44:57:03.3 |
HIP 22318 |
20.42 |
| 2026-02-09 12:00 |
04:46:31.49 |
-44:56:53.3 |
HIP 22318 |
20.53 |
| 2026-02-10 00:00 |
04:46:31.06 |
-44:56:43.4 |
HIP 22318 |
20.64 |
| 2026-02-10 12:00 |
04:46:30.63 |
-44:56:33.4 |
HIP 22318 |
20.74 |
| 2026-02-11 00:00 |
04:46:30.22 |
-44:56:23.3 |
HIP 22318 |
20.85 |
| 2026-02-11 12:00 |
04:46:29.81 |
-44:56:13.3 |
HIP 22318 |
20.96 |
| 2026-02-12 00:00 |
04:46:29.41 |
-44:56:03.1 |
HIP 22318 |
21.06 |
| 2026-02-12 12:00 |
04:46:29.02 |
-44:55:53.0 |
HIP 22318 |
21.17 |
| 2026-02-13 00:00 |
04:46:28.64 |
-44:55:42.8 |
HIP 22318 |
21.27 |
| 2026-02-13 12:00 |
04:46:28.27 |
-44:55:32.6 |
HIP 22318 |
21.37 |
| 2026-02-14 00:00 |
04:46:27.91 |
-44:55:22.3 |
HIP 22318 |
21.48 |
| 2026-02-14 12:00 |
04:46:27.56 |
-44:55:12.0 |
HIP 22318 |
21.58 |
| 2026-02-15 00:00 |
04:46:27.22 |
-44:55:01.7 |
HIP 22318 |
21.69 |
| 2026-02-15 12:00 |
04:46:26.89 |
-44:54:51.3 |
HIP 22318 |
21.79 |
| 2026-02-16 00:00 |
04:46:26.56 |
-44:54:40.9 |
HIP 22318 |
21.89 |
| 2026-02-16 12:00 |
04:46:26.25 |
-44:54:30.5 |
HIP 22318 |
21.99 |
| 2026-02-17 00:00 |
04:46:25.94 |
-44:54:20.0 |
HIP 22318 |
22.09 |
| 2026-02-17 12:00 |
04:46:25.65 |
-44:54:09.5 |
HIP 22318 |
22.20 |
| 2026-02-18 00:00 |
04:46:25.36 |
-44:53:59.0 |
HIP 22318 |
22.30 |
| 2026-02-18 12:00 |
04:46:25.08 |
-44:53:48.5 |
HIP 22318 |
22.40 |
| 2026-02-19 00:00 |
04:46:24.82 |
-44:53:37.9 |
HIP 22318 |
22.50 |
| 2026-02-19 12:00 |
04:46:24.56 |
-44:53:27.3 |
HIP 22318 |
22.60 |
| 2026-02-20 00:00 |
04:46:24.31 |
-44:53:16.7 |
HIP 22318 |
22.69 |
| 2026-02-20 12:00 |
04:46:24.07 |
-44:53:06.1 |
HIP 22318 |
22.79 |
| 2026-02-21 00:00 |
04:46:23.84 |
-44:52:55.4 |
HIP 22318 |
22.89 |
| 2026-02-21 12:00 |
04:46:23.62 |
-44:52:44.7 |
HIP 22318 |
22.99 |
| 2026-02-22 00:00 |
04:46:23.41 |
-44:52:34.0 |
HIP 22318 |
23.09 |
| 2026-02-22 12:00 |
04:46:23.21 |
-44:52:23.3 |
HIP 22318 |
23.18 |
| 2026-02-23 00:00 |
04:46:23.02 |
-44:52:12.5 |
HIP 22318 |
23.28 |
| 2026-02-23 12:00 |
04:46:22.84 |
-44:52:01.7 |
HIP 22318 |
23.38 |
| 2026-02-24 00:00 |
04:46:22.67 |
-44:51:50.9 |
HIP 22318 |
23.47 |