| 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 |
-0.500 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
06:42:31.52 |
-12:04:12.8 |
HIP 32160 |
19.27 |
| 2026-05-12 12:00 |
06:42:32.50 |
-12:04:04.0 |
HIP 32160 |
19.06 |
| 2026-05-13 00:00 |
06:42:33.48 |
-12:03:55.3 |
HIP 32160 |
18.84 |
| 2026-05-13 12:00 |
06:42:34.48 |
-12:03:46.7 |
HIP 32160 |
18.63 |
| 2026-05-14 00:00 |
06:42:35.49 |
-12:03:38.2 |
HIP 32160 |
18.43 |
| 2026-05-14 12:00 |
06:42:36.51 |
-12:03:29.7 |
HIP 32160 |
18.22 |
| 2026-05-15 00:00 |
06:42:37.53 |
-12:03:21.3 |
HIP 32160 |
18.02 |
| 2026-05-15 12:00 |
06:42:38.57 |
-12:03:13.0 |
HIP 32160 |
17.82 |
| 2026-05-16 00:00 |
06:42:39.61 |
-12:03:04.8 |
HIP 32160 |
17.63 |
| 2026-05-16 12:00 |
06:42:40.67 |
-12:02:56.7 |
HIP 32160 |
17.43 |
| 2026-05-17 00:00 |
06:42:41.73 |
-12:02:48.7 |
HIP 32160 |
17.25 |
| 2026-05-17 12:00 |
06:42:42.80 |
-12:02:40.7 |
HIP 32160 |
17.06 |
| 2026-05-18 00:00 |
06:42:43.88 |
-12:02:32.9 |
HIP 32160 |
16.88 |
| 2026-05-18 12:00 |
06:42:44.97 |
-12:02:25.1 |
HIP 32160 |
16.71 |
| 2026-05-19 00:00 |
06:42:46.06 |
-12:02:17.4 |
HIP 32160 |
16.54 |
| 2026-05-19 12:00 |
06:42:47.17 |
-12:02:09.8 |
HIP 32183 |
16.35 |
| 2026-05-20 00:00 |
06:42:48.28 |
-12:02:02.3 |
HIP 32183 |
16.15 |
| 2026-05-20 12:00 |
06:42:49.40 |
-12:01:54.9 |
HIP 32183 |
15.94 |
| 2026-05-21 00:00 |
06:42:50.53 |
-12:01:47.6 |
HIP 32183 |
15.75 |
| 2026-05-21 12:00 |
06:42:51.67 |
-12:01:40.4 |
HIP 32183 |
15.55 |
| 2026-05-22 00:00 |
06:42:52.82 |
-12:01:33.2 |
HIP 32183 |
15.36 |
| 2026-05-22 12:00 |
06:42:53.97 |
-12:01:26.2 |
HIP 32183 |
15.18 |
| 2026-05-23 00:00 |
06:42:55.13 |
-12:01:19.2 |
HIP 32183 |
15.00 |
| 2026-05-23 12:00 |
06:42:56.30 |
-12:01:12.4 |
HIP 32183 |
14.82 |
| 2026-05-24 00:00 |
06:42:57.48 |
-12:01:05.6 |
HIP 32183 |
14.65 |
| 2026-05-24 12:00 |
06:42:58.66 |
-12:00:58.9 |
HIP 32183 |
14.49 |
| 2026-05-25 00:00 |
06:42:59.85 |
-12:00:52.3 |
HIP 32183 |
14.33 |
| 2026-05-25 12:00 |
06:43:01.05 |
-12:00:45.9 |
HIP 32183 |
14.18 |
| 2026-05-26 00:00 |
06:43:02.26 |
-12:00:39.5 |
HIP 32183 |
14.03 |
| 2026-05-26 12:00 |
06:43:03.47 |
-12:00:33.2 |
HIP 32183 |
13.90 |
| 2026-05-27 00:00 |
06:43:04.69 |
-12:00:27.0 |
HIP 32183 |
13.77 |
| 2026-05-27 12:00 |
06:43:05.92 |
-12:00:20.8 |
HIP 32183 |
13.64 |
| 2026-05-28 00:00 |
06:43:07.15 |
-12:00:14.8 |
HIP 32183 |
13.53 |
| 2026-05-28 12:00 |
06:43:08.39 |
-12:00:08.9 |
HIP 32183 |
13.42 |
| 2026-05-29 00:00 |
06:43:09.64 |
-12:00:03.1 |
HIP 32183 |
13.32 |
| 2026-05-29 12:00 |
06:43:10.89 |
-11:59:57.4 |
HIP 32183 |
13.24 |
| 2026-05-30 00:00 |
06:43:12.15 |
-11:59:51.7 |
HIP 32183 |
13.15 |
| 2026-05-30 12:00 |
06:43:13.42 |
-11:59:46.2 |
HIP 32183 |
13.08 |
| 2026-05-31 00:00 |
06:43:14.69 |
-11:59:40.8 |
HIP 32183 |
13.02 |
| 2026-05-31 12:00 |
06:43:15.97 |
-11:59:35.4 |
HIP 32183 |
12.97 |
| 2026-06-01 00:00 |
06:43:17.26 |
-11:59:30.2 |
HIP 32183 |
12.93 |
| 2026-06-01 12:00 |
06:43:18.55 |
-11:59:25.1 |
HIP 32183 |
12.89 |
| 2026-06-02 00:00 |
06:43:19.85 |
-11:59:20.0 |
HIP 32183 |
12.87 |