| Parameter |
Value |
| Designation |
C/1964 P1 (Everhart) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1964-08-23T04:28:19.128000Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:16Z |
| Obs used |
40 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1964-10-14.0000000 |
| e |
0.99649619 |
| q (au) |
1.259279 |
| a (au) |
359.402401 |
| i (deg) |
67.969012 |
| Ω (om, deg) |
280.445182 |
| ω (w, deg) |
20.685810 |
| M (ma, deg) |
0.007495 |
Magnitude
Scatter + Global Linear
$$
M_a = (5.997 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
5.997 |
| 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) |
| 2026-03-26 00:00 |
06:51:53.59 |
+15:43:05.5 |
HIP 33039 |
16.88 |
| 2026-03-26 12:00 |
06:51:53.40 |
+15:43:08.0 |
HIP 33039 |
16.94 |
| 2026-03-27 00:00 |
06:51:53.23 |
+15:43:10.5 |
HIP 33039 |
16.99 |
| 2026-03-27 12:00 |
06:51:53.07 |
+15:43:13.0 |
HIP 33039 |
17.04 |
| 2026-03-28 00:00 |
06:51:52.93 |
+15:43:15.4 |
HIP 33039 |
17.08 |
| 2026-03-28 12:00 |
06:51:52.80 |
+15:43:17.9 |
HIP 33039 |
17.13 |
| 2026-03-29 00:00 |
06:51:52.67 |
+15:43:20.3 |
HIP 33039 |
17.17 |
| 2026-03-29 12:00 |
06:51:52.57 |
+15:43:22.7 |
HIP 33039 |
17.21 |
| 2026-03-30 00:00 |
06:51:52.47 |
+15:43:25.1 |
HIP 33039 |
17.24 |
| 2026-03-30 12:00 |
06:51:52.39 |
+15:43:27.5 |
HIP 33039 |
17.28 |
| 2026-03-31 00:00 |
06:51:52.32 |
+15:43:29.9 |
HIP 33039 |
17.30 |
| 2026-03-31 12:00 |
06:51:52.26 |
+15:43:32.2 |
HIP 33039 |
17.33 |
| 2026-04-01 00:00 |
06:51:52.21 |
+15:43:34.5 |
HIP 33039 |
17.36 |
| 2026-04-01 12:00 |
06:51:52.18 |
+15:43:36.9 |
HIP 33039 |
17.38 |
| 2026-04-02 00:00 |
06:51:52.16 |
+15:43:39.2 |
HIP 33039 |
17.39 |
| 2026-04-02 12:00 |
06:51:52.15 |
+15:43:41.4 |
HIP 33039 |
17.41 |
| 2026-04-03 00:00 |
06:51:52.16 |
+15:43:43.7 |
HIP 33039 |
17.42 |
| 2026-04-03 12:00 |
06:51:52.18 |
+15:43:46.0 |
HIP 33039 |
17.43 |
| 2026-04-04 00:00 |
06:51:52.20 |
+15:43:48.2 |
HIP 33039 |
17.44 |
| 2026-04-04 12:00 |
06:51:52.25 |
+15:43:50.4 |
HIP 33039 |
17.44 |
| 2026-04-05 00:00 |
06:51:52.30 |
+15:43:52.6 |
HIP 33039 |
17.44 |
| 2026-04-05 12:00 |
06:51:52.37 |
+15:43:54.8 |
HIP 33039 |
17.44 |
| 2026-04-06 00:00 |
06:51:52.45 |
+15:43:56.9 |
HIP 33039 |
17.44 |
| 2026-04-06 12:00 |
06:51:52.54 |
+15:43:59.1 |
HIP 33039 |
17.43 |
| 2026-04-07 00:00 |
06:51:52.65 |
+15:44:01.2 |
HIP 33039 |
17.42 |
| 2026-04-07 12:00 |
06:51:52.76 |
+15:44:03.3 |
HIP 33039 |
17.41 |
| 2026-04-08 00:00 |
06:51:52.89 |
+15:44:05.4 |
HIP 33039 |
17.39 |
| 2026-04-08 12:00 |
06:51:53.04 |
+15:44:07.5 |
HIP 33039 |
17.37 |
| 2026-04-09 00:00 |
06:51:53.19 |
+15:44:09.5 |
HIP 33039 |
17.35 |
| 2026-04-09 12:00 |
06:51:53.36 |
+15:44:11.6 |
HIP 33039 |
17.33 |
| 2026-04-10 00:00 |
06:51:53.54 |
+15:44:13.6 |
HIP 33039 |
17.30 |
| 2026-04-10 12:00 |
06:51:53.73 |
+15:44:15.6 |
HIP 33039 |
17.27 |
| 2026-04-11 00:00 |
06:51:53.93 |
+15:44:17.6 |
HIP 33039 |
17.24 |
| 2026-04-11 12:00 |
06:51:54.15 |
+15:44:19.5 |
HIP 33039 |
17.20 |
| 2026-04-12 00:00 |
06:51:54.38 |
+15:44:21.4 |
HIP 33039 |
17.16 |
| 2026-04-12 12:00 |
06:51:54.62 |
+15:44:23.4 |
HIP 33039 |
17.12 |
| 2026-04-13 00:00 |
06:51:54.87 |
+15:44:25.3 |
HIP 33039 |
17.08 |
| 2026-04-13 12:00 |
06:51:55.14 |
+15:44:27.1 |
HIP 33039 |
17.04 |
| 2026-04-14 00:00 |
06:51:55.41 |
+15:44:29.0 |
HIP 33039 |
16.99 |
| 2026-04-14 12:00 |
06:51:55.70 |
+15:44:30.8 |
HIP 33039 |
16.94 |
| 2026-04-15 00:00 |
06:51:56.01 |
+15:44:32.6 |
HIP 33039 |
16.88 |
| 2026-04-15 12:00 |
06:51:56.32 |
+15:44:34.4 |
HIP 33039 |
16.83 |
| 2026-04-16 00:00 |
06:51:56.65 |
+15:44:36.2 |
HIP 33039 |
16.77 |