| 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 |
0.999 |
| 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) |
| 2026-06-01 00:00 |
06:53:11.80 |
+15:45:34.1 |
HIP 33039 |
8.57 |
| 2026-06-01 12:00 |
06:53:13.01 |
+15:45:33.5 |
HIP 33039 |
8.66 |
| 2026-06-02 00:00 |
06:53:14.23 |
+15:45:32.9 |
HIP 33039 |
8.77 |
| 2026-06-02 12:00 |
06:53:15.46 |
+15:45:32.2 |
HIP 33039 |
8.88 |
| 2026-06-03 00:00 |
06:53:16.69 |
+15:45:31.5 |
HIP 33039 |
9.00 |
| 2026-06-03 12:00 |
06:53:17.93 |
+15:45:30.8 |
HIP 33039 |
9.13 |
| 2026-06-04 00:00 |
06:53:19.17 |
+15:45:30.1 |
HIP 33039 |
9.26 |
| 2026-06-04 12:00 |
06:53:20.42 |
+15:45:29.3 |
HIP 33039 |
9.41 |
| 2026-06-05 00:00 |
06:53:21.67 |
+15:45:28.5 |
HIP 33039 |
9.56 |
| 2026-06-05 12:00 |
06:53:22.93 |
+15:45:27.7 |
HIP 33039 |
9.72 |
| 2026-06-06 00:00 |
06:53:24.20 |
+15:45:26.9 |
HIP 33039 |
9.89 |
| 2026-06-06 12:00 |
06:53:25.47 |
+15:45:26.0 |
HIP 33039 |
10.06 |
| 2026-06-07 00:00 |
06:53:26.75 |
+15:45:25.1 |
HIP 33039 |
10.24 |
| 2026-06-07 12:00 |
06:53:28.03 |
+15:45:24.2 |
HIP 33039 |
10.43 |
| 2026-06-08 00:00 |
06:53:29.32 |
+15:45:23.2 |
HIP 33039 |
10.62 |
| 2026-06-08 12:00 |
06:53:30.61 |
+15:45:22.3 |
HIP 33039 |
10.82 |
| 2026-06-09 00:00 |
06:53:31.91 |
+15:45:21.3 |
HIP 33039 |
11.02 |
| 2026-06-09 12:00 |
06:53:33.21 |
+15:45:20.2 |
HIP 33039 |
11.23 |
| 2026-06-10 00:00 |
06:53:34.52 |
+15:45:19.2 |
HIP 33039 |
11.45 |
| 2026-06-10 12:00 |
06:53:35.83 |
+15:45:18.1 |
HIP 33039 |
11.67 |
| 2026-06-11 00:00 |
06:53:37.15 |
+15:45:17.0 |
HIP 33039 |
11.90 |
| 2026-06-11 12:00 |
06:53:38.47 |
+15:45:15.8 |
HIP 33039 |
12.13 |
| 2026-06-12 00:00 |
06:53:39.79 |
+15:45:14.7 |
HIP 33039 |
12.36 |
| 2026-06-12 12:00 |
06:53:41.12 |
+15:45:13.5 |
HIP 33039 |
12.60 |
| 2026-06-13 00:00 |
06:53:42.46 |
+15:45:12.3 |
HIP 33039 |
12.84 |
| 2026-06-13 12:00 |
06:53:43.80 |
+15:45:11.0 |
HIP 33039 |
13.09 |
| 2026-06-14 00:00 |
06:53:45.14 |
+15:45:09.7 |
HIP 33039 |
13.34 |
| 2026-06-14 12:00 |
06:53:46.49 |
+15:45:08.4 |
HIP 33039 |
13.60 |
| 2026-06-15 00:00 |
06:53:47.84 |
+15:45:07.1 |
HIP 33205 |
13.52 |
| 2026-06-15 12:00 |
06:53:49.19 |
+15:45:05.8 |
HIP 33205 |
13.23 |
| 2026-06-16 00:00 |
06:53:50.55 |
+15:45:04.4 |
HIP 33205 |
12.94 |
| 2026-06-16 12:00 |
06:53:51.91 |
+15:45:03.0 |
HIP 33205 |
12.65 |
| 2026-06-17 00:00 |
06:53:53.28 |
+15:45:01.6 |
HIP 33205 |
12.36 |
| 2026-06-17 12:00 |
06:53:54.64 |
+15:45:00.1 |
HIP 33205 |
12.07 |
| 2026-06-18 00:00 |
06:53:56.01 |
+15:44:58.6 |
HIP 33205 |
11.79 |
| 2026-06-18 12:00 |
06:53:57.39 |
+15:44:57.1 |
HIP 33205 |
11.51 |
| 2026-06-19 00:00 |
06:53:58.77 |
+15:44:55.6 |
HIP 33205 |
11.23 |
| 2026-06-19 12:00 |
06:54:00.15 |
+15:44:54.0 |
HIP 33205 |
10.95 |
| 2026-06-20 00:00 |
06:54:01.53 |
+15:44:52.4 |
HIP 33205 |
10.67 |
| 2026-06-20 12:00 |
06:54:02.92 |
+15:44:50.8 |
HIP 33205 |
10.40 |
| 2026-06-21 00:00 |
06:54:04.31 |
+15:44:49.2 |
HIP 33205 |
10.13 |
| 2026-06-21 12:00 |
06:54:05.70 |
+15:44:47.5 |
HIP 33205 |
9.87 |
| 2026-06-22 00:00 |
06:54:07.09 |
+15:44:45.9 |
HIP 33205 |
9.61 |