| 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) |
| 2026-07-29 00:00 |
05:38:05.70 |
+30:35:26.9 |
HIP 26536 |
9.14 |
| 2026-07-29 12:00 |
05:38:51.05 |
+30:36:24.0 |
HIP 26536 |
7.40 |
| 2026-07-30 00:00 |
05:39:36.24 |
+30:37:20.5 |
HIP 26536 |
14.75 |
| 2026-07-30 12:00 |
05:40:21.28 |
+30:38:16.3 |
HIP 26611 |
19.43 |
| 2026-07-31 00:00 |
05:41:06.17 |
+30:39:11.5 |
HIP 26854 |
24.71 |
| 2026-07-31 12:00 |
05:41:50.90 |
+30:40:06.1 |
HIP 26946 |
20.85 |
| 2026-08-01 00:00 |
05:42:35.49 |
+30:41:00.1 |
HIP 26946 |
14.39 |
| 2026-08-01 12:00 |
05:43:19.91 |
+30:41:53.5 |
HIP 26946 |
12.82 |
| 2026-08-02 00:00 |
05:44:04.18 |
+30:42:46.3 |
HIP 27040 |
13.26 |
| 2026-08-02 12:00 |
05:44:48.30 |
+30:43:38.5 |
HIP 27077 |
14.83 |
| 2026-08-03 00:00 |
05:45:32.25 |
+30:44:30.1 |
HIP 27077 |
20.13 |
| 2026-08-03 12:00 |
05:46:16.05 |
+30:45:21.2 |
HIP 27398 |
25.24 |
| 2026-08-04 00:00 |
05:46:59.69 |
+30:46:11.7 |
HIP 27398 |
16.92 |
| 2026-08-04 12:00 |
05:47:43.16 |
+30:47:01.7 |
HIP 27398 |
10.62 |
| 2026-08-05 00:00 |
05:48:26.48 |
+30:47:51.1 |
HIP 27398 |
10.73 |
| 2026-08-05 12:00 |
05:49:09.64 |
+30:48:40.0 |
HIP 27398 |
17.06 |
| 2026-08-06 00:00 |
05:49:52.63 |
+30:49:28.4 |
HIP 27548 |
15.94 |
| 2026-08-06 12:00 |
05:50:35.45 |
+30:50:16.3 |
HIP 27582 |
13.71 |
| 2026-08-07 00:00 |
05:51:18.11 |
+30:51:03.7 |
HIP 27675 |
13.71 |
| 2026-08-07 12:00 |
05:52:00.61 |
+30:51:50.6 |
HIP 27675 |
15.50 |
| 2026-08-08 00:00 |
05:52:42.93 |
+30:52:37.0 |
HIP 27825 |
20.97 |
| 2026-08-08 12:00 |
05:53:25.09 |
+30:53:22.9 |
HIP 27825 |
20.52 |
| 2026-08-09 00:00 |
05:54:07.08 |
+30:54:08.4 |
HIP 28022 |
22.39 |
| 2026-08-09 12:00 |
05:54:48.90 |
+30:54:53.4 |
HIP 28022 |
15.94 |
| 2026-08-10 00:00 |
05:55:30.54 |
+30:55:38.0 |
HIP 28022 |
13.02 |
| 2026-08-10 12:00 |
05:56:12.01 |
+30:56:22.2 |
HIP 28022 |
15.65 |
| 2026-08-11 00:00 |
05:56:53.30 |
+30:57:05.9 |
HIP 28157 |
20.57 |
| 2026-08-11 12:00 |
05:57:34.42 |
+30:57:49.2 |
HIP 28324 |
19.38 |
| 2026-08-12 00:00 |
05:58:15.36 |
+30:58:32.1 |
HIP 28324 |
10.70 |
| 2026-08-12 12:00 |
05:58:56.12 |
+30:59:14.6 |
HIP 28324 |
2.95 |
| 2026-08-13 00:00 |
05:59:36.70 |
+30:59:56.7 |
HIP 28324 |
7.48 |
| 2026-08-13 12:00 |
06:00:17.10 |
+31:00:38.4 |
HIP 28517 |
11.43 |
| 2026-08-14 00:00 |
06:00:57.32 |
+31:01:19.8 |
HIP 28517 |
2.83 |
| 2026-08-14 12:00 |
06:01:37.35 |
+31:02:00.8 |
HIP 28517 |
5.85 |
| 2026-08-15 00:00 |
06:02:17.20 |
+31:02:41.4 |
HIP 28517 |
14.40 |
| 2026-08-15 12:00 |
06:02:56.86 |
+31:03:21.7 |
HIP 28715 |
20.35 |
| 2026-08-16 00:00 |
06:03:36.34 |
+31:04:01.7 |
HIP 28715 |
16.09 |
| 2026-08-16 12:00 |
06:04:15.63 |
+31:04:41.4 |
HIP 28715 |
15.72 |
| 2026-08-17 00:00 |
06:04:54.73 |
+31:05:20.7 |
HIP 28715 |
19.40 |
| 2026-08-17 12:00 |
06:05:33.64 |
+31:05:59.8 |
HIP 28929 |
21.45 |
| 2026-08-18 00:00 |
06:06:12.35 |
+31:06:38.5 |
HIP 28929 |
18.28 |
| 2026-08-18 12:00 |
06:06:50.88 |
+31:07:17.0 |
HIP 28929 |
18.58 |
| 2026-08-19 00:00 |
06:07:29.21 |
+31:07:55.1 |
HIP 29116 |
12.62 |