| Parameter |
Value |
| Designation |
C/1954 O2 (Baade) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1955-08-13T07:51:21.994560Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:12Z |
| Obs used |
35 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1955-09-19.0000000 |
| e |
1.00055852 |
| q (au) |
3.869944 |
| a (au) |
-6928.925768 |
| i (deg) |
100.387736 |
| Ω (om, deg) |
265.340699 |
| ω (w, deg) |
144.674890 |
| M (ma, deg) |
0.000063 |
Magnitude
Scatter + Global Linear
$$
M_a = (-0.462 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
-0.462 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.500 |
| k |
1.000 |
| δ90 |
10.000 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 1955-09-09 |
1957-11-02 |
+4.8428 |
-3.023 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
20:40:57.45 |
-79:23:07.2 |
HIP 102428 |
21.56 |
| 2026-05-12 12:00 |
20:40:55.83 |
-79:23:23.7 |
HIP 102428 |
21.83 |
| 2026-05-13 00:00 |
20:40:54.14 |
-79:23:40.2 |
HIP 102428 |
22.10 |
| 2026-05-13 12:00 |
20:40:52.40 |
-79:23:56.6 |
HIP 102428 |
22.37 |
| 2026-05-14 00:00 |
20:40:50.60 |
-79:24:13.0 |
HIP 102428 |
22.64 |
| 2026-05-14 12:00 |
20:40:48.75 |
-79:24:29.4 |
HIP 102428 |
22.91 |
| 2026-05-15 00:00 |
20:40:46.83 |
-79:24:45.8 |
HIP 102428 |
23.19 |
| 2026-05-15 12:00 |
20:40:44.86 |
-79:25:02.2 |
HIP 102428 |
23.47 |
| 2026-05-16 00:00 |
20:40:42.84 |
-79:25:18.5 |
HIP 102428 |
23.74 |
| 2026-05-16 12:00 |
20:40:40.75 |
-79:25:34.8 |
HIP 102428 |
24.02 |
| 2026-05-17 00:00 |
20:40:38.61 |
-79:25:51.1 |
HIP 102428 |
24.31 |
| 2026-05-17 12:00 |
20:40:36.42 |
-79:26:07.4 |
HIP 102428 |
24.59 |
| 2026-05-18 00:00 |
20:40:34.17 |
-79:26:23.6 |
HIP 102428 |
24.87 |
| 2026-05-18 12:00 |
20:40:31.86 |
-79:26:39.9 |
HIP 102428 |
25.15 |
| 2026-05-19 00:00 |
20:40:29.49 |
-79:26:56.1 |
HIP 102428 |
25.44 |
| 2026-05-19 12:00 |
20:40:27.07 |
-79:27:12.2 |
HIP 102428 |
25.73 |
| 2026-05-20 00:00 |
20:40:24.59 |
-79:27:28.3 |
HIP 102428 |
26.01 |
| 2026-05-20 12:00 |
20:40:22.06 |
-79:27:44.4 |
HIP 102428 |
26.30 |
| 2026-05-21 00:00 |
20:40:19.47 |
-79:28:00.5 |
HIP 102428 |
26.59 |
| 2026-05-21 12:00 |
20:40:16.83 |
-79:28:16.5 |
HIP 102428 |
26.88 |
| 2026-05-22 00:00 |
20:40:14.13 |
-79:28:32.5 |
HIP 102428 |
27.17 |
| 2026-05-22 12:00 |
20:40:11.38 |
-79:28:48.5 |
HIP 102428 |
27.47 |
| 2026-05-23 00:00 |
20:40:08.57 |
-79:29:04.4 |
HIP 102428 |
27.76 |
| 2026-05-23 12:00 |
20:40:05.71 |
-79:29:20.2 |
HIP 102428 |
28.05 |
| 2026-05-24 00:00 |
20:40:02.79 |
-79:29:36.1 |
HIP 102428 |
28.35 |
| 2026-05-24 12:00 |
20:39:59.82 |
-79:29:51.8 |
HIP 102428 |
28.64 |
| 2026-05-25 00:00 |
20:39:56.79 |
-79:30:07.6 |
HIP 102428 |
28.94 |
| 2026-05-25 12:00 |
20:39:53.71 |
-79:30:23.3 |
HIP 102428 |
29.23 |
| 2026-05-26 00:00 |
20:39:50.58 |
-79:30:38.9 |
HIP 102608 |
29.29 |
| 2026-05-26 12:00 |
20:39:47.39 |
-79:30:54.5 |
HIP 102608 |
29.21 |
| 2026-05-27 00:00 |
20:39:44.15 |
-79:31:10.0 |
HIP 102608 |
29.13 |
| 2026-05-27 12:00 |
20:39:40.85 |
-79:31:25.5 |
HIP 102608 |
29.06 |
| 2026-05-28 00:00 |
20:39:37.51 |
-79:31:41.0 |
HIP 102608 |
28.99 |
| 2026-05-28 12:00 |
20:39:34.11 |
-79:31:56.4 |
HIP 102608 |
28.93 |
| 2026-05-29 00:00 |
20:39:30.65 |
-79:32:11.7 |
HIP 102608 |
28.87 |
| 2026-05-29 12:00 |
20:39:27.15 |
-79:32:27.0 |
HIP 102608 |
28.82 |
| 2026-05-30 00:00 |
20:39:23.59 |
-79:32:42.2 |
HIP 102608 |
28.77 |
| 2026-05-30 12:00 |
20:39:19.98 |
-79:32:57.4 |
HIP 102608 |
28.73 |
| 2026-05-31 00:00 |
20:39:16.32 |
-79:33:12.5 |
HIP 102608 |
28.70 |
| 2026-05-31 12:00 |
20:39:12.61 |
-79:33:27.5 |
HIP 102608 |
28.67 |
| 2026-06-01 00:00 |
20:39:08.85 |
-79:33:42.5 |
HIP 102608 |
28.64 |
| 2026-06-01 12:00 |
20:39:05.03 |
-79:33:57.5 |
HIP 102608 |
28.62 |
| 2026-06-02 00:00 |
20:39:01.16 |
-79:34:12.3 |
HIP 102608 |
28.61 |