| Parameter |
Value |
| Designation |
C/1963 R1 (Pereyra) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1963-08-23T23:19:43.055040Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:17Z |
| Obs used |
12 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1963-10-25.0000000 |
| e |
0.99994492 |
| q (au) |
0.005021 |
| a (au) |
91.149463 |
| i (deg) |
144.594816 |
| Ω (om, deg) |
8.051859 |
| ω (w, deg) |
86.230920 |
| M (ma, deg) |
0.070252 |
Magnitude
Scatter + Global Linear
$$
M_a = (4.625 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
4.625 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.998 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
06:47:39.08 |
-12:19:31.4 |
HIP 32513 |
10.89 |
| 2026-09-20 12:00 |
06:47:39.42 |
-12:19:44.2 |
HIP 32513 |
11.10 |
| 2026-09-21 00:00 |
06:47:39.75 |
-12:19:57.1 |
HIP 32513 |
11.31 |
| 2026-09-21 12:00 |
06:47:40.06 |
-12:20:10.0 |
HIP 32513 |
11.52 |
| 2026-09-22 00:00 |
06:47:40.36 |
-12:20:22.9 |
HIP 32513 |
11.72 |
| 2026-09-22 12:00 |
06:47:40.65 |
-12:20:35.8 |
HIP 32513 |
11.93 |
| 2026-09-23 00:00 |
06:47:40.93 |
-12:20:48.8 |
HIP 32513 |
12.13 |
| 2026-09-23 12:00 |
06:47:41.19 |
-12:21:01.7 |
HIP 32513 |
12.33 |
| 2026-09-24 00:00 |
06:47:41.44 |
-12:21:14.7 |
HIP 32513 |
12.53 |
| 2026-09-24 12:00 |
06:47:41.68 |
-12:21:27.6 |
HIP 32513 |
12.73 |
| 2026-09-25 00:00 |
06:47:41.90 |
-12:21:40.6 |
HIP 32513 |
12.93 |
| 2026-09-25 12:00 |
06:47:42.12 |
-12:21:53.6 |
HIP 32513 |
13.13 |
| 2026-09-26 00:00 |
06:47:42.32 |
-12:22:06.5 |
HIP 32513 |
13.32 |
| 2026-09-26 12:00 |
06:47:42.50 |
-12:22:19.5 |
HIP 32513 |
13.52 |
| 2026-09-27 00:00 |
06:47:42.68 |
-12:22:32.5 |
HIP 32513 |
13.71 |
| 2026-09-27 12:00 |
06:47:42.84 |
-12:22:45.5 |
HIP 32513 |
13.91 |
| 2026-09-28 00:00 |
06:47:42.99 |
-12:22:58.5 |
HIP 32513 |
14.10 |
| 2026-09-28 12:00 |
06:47:43.12 |
-12:23:11.5 |
HIP 32513 |
14.29 |
| 2026-09-29 00:00 |
06:47:43.25 |
-12:23:24.5 |
HIP 32513 |
14.48 |
| 2026-09-29 12:00 |
06:47:43.36 |
-12:23:37.5 |
HIP 32513 |
14.67 |
| 2026-09-30 00:00 |
06:47:43.45 |
-12:23:50.5 |
HIP 32513 |
14.85 |
| 2026-09-30 12:00 |
06:47:43.54 |
-12:24:03.5 |
HIP 32513 |
15.04 |
| 2026-10-01 00:00 |
06:47:43.61 |
-12:24:16.5 |
HIP 32513 |
15.22 |
| 2026-10-01 12:00 |
06:47:43.67 |
-12:24:29.5 |
HIP 32513 |
15.41 |
| 2026-10-02 00:00 |
06:47:43.71 |
-12:24:42.5 |
HIP 32513 |
15.59 |
| 2026-10-02 12:00 |
06:47:43.74 |
-12:24:55.5 |
HIP 32513 |
15.77 |
| 2026-10-03 00:00 |
06:47:43.76 |
-12:25:08.5 |
HIP 32513 |
15.95 |
| 2026-10-03 12:00 |
06:47:43.77 |
-12:25:21.4 |
HIP 32513 |
16.13 |
| 2026-10-04 00:00 |
06:47:43.76 |
-12:25:34.4 |
HIP 32513 |
16.31 |
| 2026-10-04 12:00 |
06:47:43.74 |
-12:25:47.4 |
HIP 32513 |
16.49 |
| 2026-10-05 00:00 |
06:47:43.71 |
-12:26:00.3 |
HIP 32513 |
16.67 |
| 2026-10-05 12:00 |
06:47:43.66 |
-12:26:13.2 |
HIP 32513 |
16.85 |
| 2026-10-06 00:00 |
06:47:43.60 |
-12:26:26.1 |
HIP 32513 |
17.02 |
| 2026-10-06 12:00 |
06:47:43.53 |
-12:26:39.1 |
HIP 32513 |
17.19 |
| 2026-10-07 00:00 |
06:47:43.44 |
-12:26:51.9 |
HIP 32513 |
17.37 |
| 2026-10-07 12:00 |
06:47:43.34 |
-12:27:04.8 |
HIP 32513 |
17.54 |
| 2026-10-08 00:00 |
06:47:43.23 |
-12:27:17.7 |
HIP 32513 |
17.71 |
| 2026-10-08 12:00 |
06:47:43.10 |
-12:27:30.5 |
HIP 32513 |
17.88 |
| 2026-10-09 00:00 |
06:47:42.97 |
-12:27:43.4 |
HIP 32513 |
18.05 |
| 2026-10-09 12:00 |
06:47:42.81 |
-12:27:56.2 |
HIP 32513 |
18.22 |
| 2026-10-10 00:00 |
06:47:42.65 |
-12:28:08.9 |
HIP 32513 |
18.39 |
| 2026-10-10 12:00 |
06:47:42.47 |
-12:28:21.7 |
HIP 32513 |
18.56 |
| 2026-10-11 00:00 |
06:47:42.28 |
-12:28:34.4 |
HIP 32513 |
18.72 |