D/1884 O1 (Barnard)
| Parameter |
Value |
| Designation |
D/1884 O1 (Barnard) |
| Type |
D |
| Perihelion (tp_cal, UTC) |
1884-08-16T23:21:01.497600Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:28:51Z |
| Obs used |
19 |
| NEO |
Yes |
| M1 |
- |
| K1 |
- |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1884-08-23.0000000 |
| e |
0.58359434 |
| q (au) |
1.279598 |
| a (au) |
3.072961 |
| i (deg) |
5.473223 |
| Ω (om, deg) |
6.750708 |
| ω (w, deg) |
301.053763 |
| M (ma, deg) |
1.102744 |
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 |
23:28:05.21 |
+01:18:37.3 |
HIP 115768 |
16.90 |
| 2026-02-03 12:00 |
23:29:27.11 |
+01:28:47.0 |
HIP 115984 |
20.28 |
| 2026-02-04 00:00 |
23:30:48.82 |
+01:38:55.1 |
HIP 116012 |
21.89 |
| 2026-02-04 12:00 |
23:32:10.35 |
+01:49:01.7 |
HIP 116012 |
29.47 |
| 2026-02-05 00:00 |
23:33:31.69 |
+01:59:06.6 |
HIP 116410 |
31.32 |
| 2026-02-05 12:00 |
23:34:52.84 |
+02:09:10.0 |
HIP 116410 |
8.70 |
| 2026-02-06 00:00 |
23:36:13.80 |
+02:19:11.8 |
HIP 116463 |
8.88 |
| 2026-02-06 12:00 |
23:37:34.58 |
+02:29:11.9 |
HIP 116660 |
19.31 |
| 2026-02-07 00:00 |
23:38:55.18 |
+02:39:10.4 |
HIP 116786 |
21.75 |
| 2026-02-07 12:00 |
23:40:15.61 |
+02:49:07.2 |
HIP 116786 |
3.96 |
| 2026-02-08 00:00 |
23:41:35.85 |
+02:59:02.4 |
HIP 116786 |
23.67 |
| 2026-02-08 12:00 |
23:42:55.91 |
+03:08:56.0 |
HIP 116866 |
37.77 |
| 2026-02-09 00:00 |
23:44:15.81 |
+03:18:47.8 |
HIP 117148 |
29.48 |
| 2026-02-09 12:00 |
23:45:35.52 |
+03:28:38.0 |
HIP 117245 |
12.00 |
| 2026-02-10 00:00 |
23:46:55.07 |
+03:38:26.5 |
HIP 117245 |
12.13 |
| 2026-02-10 12:00 |
23:48:14.44 |
+03:48:13.2 |
HIP 117474 |
22.03 |
| 2026-02-11 00:00 |
23:49:33.65 |
+03:57:58.3 |
HIP 117474 |
26.75 |
| 2026-02-11 12:00 |
23:50:52.69 |
+04:07:41.6 |
HIP 117530 |
23.09 |
| 2026-02-12 00:00 |
23:52:11.56 |
+04:17:23.2 |
HIP 117656 |
25.70 |
| 2026-02-12 12:00 |
23:53:30.26 |
+04:27:03.0 |
HIP 117804 |
21.74 |
| 2026-02-13 00:00 |
23:54:48.81 |
+04:36:41.1 |
HIP 117847 |
18.99 |
| 2026-02-13 12:00 |
23:56:07.19 |
+04:46:17.4 |
HIP 118013 |
9.10 |
| 2026-02-14 00:00 |
23:57:25.41 |
+04:55:51.9 |
HIP 118054 |
15.58 |
| 2026-02-14 12:00 |
23:58:43.47 |
+05:05:24.6 |
HIP 118137 |
23.43 |
| 2026-02-15 00:00 |
00:00:01.37 |
+05:14:55.6 |
HIP 129 |
25.59 |
| 2026-02-15 12:00 |
00:01:19.11 |
+05:24:24.7 |
HIP 129 |
5.53 |
| 2026-02-16 00:00 |
00:02:36.70 |
+05:33:52.1 |
HIP 129 |
18.25 |
| 2026-02-16 12:00 |
00:03:54.13 |
+05:43:17.6 |
HIP 219 |
25.35 |
| 2026-02-17 00:00 |
00:05:11.41 |
+05:52:41.3 |
HIP 538 |
20.21 |
| 2026-02-17 12:00 |
00:06:28.54 |
+06:02:03.2 |
HIP 538 |
12.56 |
| 2026-02-18 00:00 |
00:07:45.52 |
+06:11:23.2 |
HIP 593 |
8.23 |
| 2026-02-18 12:00 |
00:09:02.34 |
+06:20:41.4 |
HIP 682 |
18.69 |
| 2026-02-19 00:00 |
00:10:19.02 |
+06:29:57.7 |
HIP 907 |
23.55 |
| 2026-02-19 12:00 |
00:11:35.55 |
+06:39:12.1 |
HIP 933 |
28.09 |
| 2026-02-20 00:00 |
00:12:51.93 |
+06:48:24.7 |
HIP 1095 |
18.16 |
| 2026-02-20 12:00 |
00:14:08.16 |
+06:57:35.4 |
HIP 1130 |
4.95 |
| 2026-02-21 00:00 |
00:15:24.25 |
+07:06:44.2 |
HIP 1130 |
24.07 |
| 2026-02-21 12:00 |
00:16:40.20 |
+07:15:51.1 |
HIP 1535 |
36.55 |
| 2026-02-22 00:00 |
00:17:56.00 |
+07:24:56.1 |
HIP 1535 |
19.45 |
| 2026-02-22 12:00 |
00:19:11.66 |
+07:33:59.2 |
HIP 1535 |
17.07 |
| 2026-02-23 00:00 |
00:20:27.18 |
+07:43:00.4 |
HIP 1645 |
28.49 |
| 2026-02-23 12:00 |
00:21:42.55 |
+07:51:59.7 |
HIP 1767 |
9.94 |
| 2026-02-24 00:00 |
00:22:57.79 |
+08:00:57.0 |
HIP 1767 |
11.80 |