| 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) |
| 2026-06-01 00:00 |
03:56:22.37 |
+26:57:31.0 |
HIP 18439 |
13.09 |
| 2026-06-01 12:00 |
03:57:20.79 |
+27:00:33.9 |
HIP 18439 |
19.44 |
| 2026-06-02 00:00 |
03:58:19.12 |
+27:03:35.4 |
HIP 18621 |
13.21 |
| 2026-06-02 12:00 |
03:59:17.37 |
+27:06:35.4 |
HIP 18621 |
5.89 |
| 2026-06-03 00:00 |
04:00:15.54 |
+27:09:34.0 |
HIP 18621 |
15.75 |
| 2026-06-03 12:00 |
04:01:13.63 |
+27:12:31.1 |
HIP 18779 |
24.50 |
| 2026-06-04 00:00 |
04:02:11.63 |
+27:15:26.8 |
HIP 18779 |
23.80 |
| 2026-06-04 12:00 |
04:03:09.55 |
+27:18:21.1 |
HIP 18779 |
29.69 |
| 2026-06-05 00:00 |
04:04:07.38 |
+27:21:13.9 |
HIP 19068 |
21.04 |
| 2026-06-05 12:00 |
04:05:05.13 |
+27:24:05.4 |
HIP 19068 |
12.60 |
| 2026-06-06 00:00 |
04:06:02.80 |
+27:26:55.4 |
HIP 19186 |
10.09 |
| 2026-06-06 12:00 |
04:07:00.38 |
+27:29:44.0 |
HIP 19219 |
2.27 |
| 2026-06-07 00:00 |
04:07:57.87 |
+27:32:31.3 |
HIP 19219 |
10.81 |
| 2026-06-07 12:00 |
04:08:55.28 |
+27:35:17.1 |
HIP 19219 |
23.82 |
| 2026-06-08 00:00 |
04:09:52.61 |
+27:38:01.6 |
HIP 19382 |
32.67 |
| 2026-06-08 12:00 |
04:10:49.85 |
+27:40:44.6 |
HIP 19592 |
35.22 |
| 2026-06-09 00:00 |
04:11:47.00 |
+27:43:26.3 |
HIP 19592 |
34.75 |
| 2026-06-09 12:00 |
04:12:44.06 |
+27:46:06.7 |
HIP 19792 |
26.40 |
| 2026-06-10 00:00 |
04:13:41.04 |
+27:48:45.6 |
HIP 19792 |
14.25 |
| 2026-06-10 12:00 |
04:14:37.92 |
+27:51:23.3 |
HIP 19792 |
6.35 |
| 2026-06-11 00:00 |
04:15:34.72 |
+27:53:59.5 |
HIP 19792 |
14.39 |
| 2026-06-11 12:00 |
04:16:31.43 |
+27:56:34.4 |
HIP 19792 |
26.47 |
| 2026-06-12 00:00 |
04:17:28.05 |
+27:59:08.0 |
HIP 20090 |
14.85 |
| 2026-06-12 12:00 |
04:18:24.58 |
+28:01:40.2 |
HIP 20090 |
4.56 |
| 2026-06-13 00:00 |
04:19:21.02 |
+28:04:11.2 |
HIP 20090 |
12.02 |
| 2026-06-13 12:00 |
04:20:17.36 |
+28:06:40.7 |
HIP 20090 |
24.28 |
| 2026-06-14 00:00 |
04:21:13.62 |
+28:09:09.0 |
HIP 20388 |
13.40 |
| 2026-06-14 12:00 |
04:22:09.78 |
+28:11:36.0 |
HIP 20388 |
6.94 |
| 2026-06-15 00:00 |
04:23:05.84 |
+28:14:01.6 |
HIP 20512 |
8.85 |
| 2026-06-15 12:00 |
04:24:01.82 |
+28:16:25.9 |
HIP 20512 |
6.56 |
| 2026-06-16 00:00 |
04:24:57.69 |
+28:18:49.0 |
HIP 20512 |
17.95 |
| 2026-06-16 12:00 |
04:25:53.47 |
+28:21:10.7 |
HIP 20512 |
30.22 |
| 2026-06-17 00:00 |
04:26:49.16 |
+28:23:31.2 |
HIP 20864 |
41.58 |
| 2026-06-17 12:00 |
04:27:44.74 |
+28:25:50.4 |
HIP 21010 |
38.59 |
| 2026-06-18 00:00 |
04:28:40.23 |
+28:28:08.3 |
HIP 21010 |
29.85 |
| 2026-06-18 12:00 |
04:29:35.62 |
+28:30:25.0 |
HIP 21010 |
24.53 |
| 2026-06-19 00:00 |
04:30:30.91 |
+28:32:40.4 |
HIP 21010 |
24.88 |
| 2026-06-19 12:00 |
04:31:26.10 |
+28:34:54.5 |
HIP 21159 |
27.82 |
| 2026-06-20 00:00 |
04:32:21.19 |
+28:37:07.4 |
HIP 21262 |
19.11 |
| 2026-06-20 12:00 |
04:33:16.18 |
+28:39:19.0 |
HIP 21262 |
7.36 |
| 2026-06-21 00:00 |
04:34:11.06 |
+28:41:29.5 |
HIP 21262 |
6.59 |
| 2026-06-21 12:00 |
04:35:05.85 |
+28:43:38.6 |
HIP 21323 |
15.30 |
| 2026-06-22 00:00 |
04:36:00.53 |
+28:45:46.6 |
HIP 21323 |
21.64 |