| 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) |
| 2026-03-26 00:00 |
01:34:35.40 |
+15:58:13.3 |
HIP 7300 |
14.64 |
| 2026-03-26 12:00 |
01:35:43.95 |
+16:05:10.4 |
HIP 7405 |
15.66 |
| 2026-03-27 00:00 |
01:36:52.40 |
+16:12:05.4 |
HIP 7608 |
18.87 |
| 2026-03-27 12:00 |
01:38:00.77 |
+16:18:58.5 |
HIP 7608 |
2.73 |
| 2026-03-28 00:00 |
01:39:09.05 |
+16:25:49.6 |
HIP 7740 |
7.75 |
| 2026-03-28 12:00 |
01:40:17.25 |
+16:32:38.8 |
HIP 7740 |
12.05 |
| 2026-03-29 00:00 |
01:41:25.35 |
+16:39:26.0 |
HIP 7867 |
9.07 |
| 2026-03-29 12:00 |
01:42:33.37 |
+16:46:11.3 |
HIP 7930 |
19.36 |
| 2026-03-30 00:00 |
01:43:41.31 |
+16:52:54.5 |
HIP 7930 |
27.08 |
| 2026-03-30 12:00 |
01:44:49.15 |
+16:59:35.9 |
HIP 8271 |
35.71 |
| 2026-03-31 00:00 |
01:45:56.92 |
+17:06:15.2 |
HIP 8309 |
20.65 |
| 2026-03-31 12:00 |
01:47:04.60 |
+17:12:52.7 |
HIP 8309 |
4.60 |
| 2026-04-01 00:00 |
01:48:12.19 |
+17:19:28.2 |
HIP 8309 |
15.01 |
| 2026-04-01 12:00 |
01:49:19.70 |
+17:26:01.7 |
HIP 8489 |
21.05 |
| 2026-04-02 00:00 |
01:50:27.13 |
+17:32:33.3 |
HIP 8489 |
20.40 |
| 2026-04-02 12:00 |
01:51:34.48 |
+17:39:03.0 |
HIP 8726 |
19.33 |
| 2026-04-03 00:00 |
01:52:41.75 |
+17:45:30.7 |
HIP 8726 |
12.22 |
| 2026-04-03 12:00 |
01:53:48.94 |
+17:51:56.5 |
HIP 8726 |
22.80 |
| 2026-04-04 00:00 |
01:54:56.04 |
+17:58:20.4 |
HIP 8915 |
25.29 |
| 2026-04-04 12:00 |
01:56:03.07 |
+18:04:42.3 |
HIP 9012 |
22.06 |
| 2026-04-05 00:00 |
01:57:10.01 |
+18:11:02.4 |
HIP 9193 |
17.80 |
| 2026-04-05 12:00 |
01:58:16.88 |
+18:17:20.5 |
HIP 9193 |
1.39 |
| 2026-04-06 00:00 |
01:59:23.67 |
+18:23:36.7 |
HIP 9248 |
7.25 |
| 2026-04-06 12:00 |
02:00:30.39 |
+18:29:51.0 |
HIP 9248 |
24.24 |
| 2026-04-07 00:00 |
02:01:37.02 |
+18:36:03.4 |
HIP 9602 |
31.28 |
| 2026-04-07 12:00 |
02:02:43.58 |
+18:42:13.9 |
HIP 9602 |
25.05 |
| 2026-04-08 00:00 |
02:03:50.06 |
+18:48:22.5 |
HIP 9602 |
29.14 |
| 2026-04-08 12:00 |
02:04:56.47 |
+18:54:29.2 |
HIP 9725 |
16.94 |
| 2026-04-09 00:00 |
02:06:02.80 |
+19:00:34.1 |
HIP 9725 |
17.02 |
| 2026-04-09 12:00 |
02:07:09.06 |
+19:06:37.0 |
HIP 9959 |
21.14 |
| 2026-04-10 00:00 |
02:08:15.24 |
+19:12:38.0 |
HIP 9959 |
9.10 |
| 2026-04-10 12:00 |
02:09:21.35 |
+19:18:37.2 |
HIP 9959 |
16.69 |
| 2026-04-11 00:00 |
02:10:27.38 |
+19:24:34.5 |
HIP 10155 |
5.95 |
| 2026-04-11 12:00 |
02:11:33.34 |
+19:30:29.9 |
HIP 10155 |
13.16 |
| 2026-04-12 00:00 |
02:12:39.23 |
+19:36:23.5 |
HIP 10318 |
13.32 |
| 2026-04-12 12:00 |
02:13:45.04 |
+19:42:15.1 |
HIP 10390 |
5.61 |
| 2026-04-13 00:00 |
02:14:50.78 |
+19:48:04.9 |
HIP 10390 |
17.87 |
| 2026-04-13 12:00 |
02:15:56.45 |
+19:53:52.9 |
HIP 10494 |
23.91 |
| 2026-04-14 00:00 |
02:17:02.04 |
+19:59:39.0 |
HIP 10732 |
16.37 |
| 2026-04-14 12:00 |
02:18:07.57 |
+20:05:23.2 |
HIP 10732 |
11.32 |
| 2026-04-15 00:00 |
02:19:13.02 |
+20:11:05.6 |
HIP 10732 |
22.94 |
| 2026-04-15 12:00 |
02:20:18.39 |
+20:16:46.1 |
HIP 11032 |
27.91 |
| 2026-04-16 00:00 |
02:21:23.70 |
+20:22:24.7 |
HIP 11032 |
11.83 |