| Parameter |
Value |
| Designation |
C/1964 N1 (Ikeya) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1964-08-01T05:13:48.668160Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:16Z |
| Obs used |
36 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1964-07-28.0000000 |
| e |
0.98529909 |
| q (au) |
0.821742 |
| a (au) |
55.897329 |
| i (deg) |
171.919437 |
| Ω (om, deg) |
269.947994 |
| ω (w, deg) |
290.768689 |
| M (ma, deg) |
359.990052 |
Magnitude
Scatter + Global Linear
$$
M_a = (7.144 + 3.169\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
7.144 |
| n |
3.169 |
| gf |
0.800 |
| gb |
-0.500 |
| k |
0.800 |
| δ90 |
1.000 |
| 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 |
11:21:09.84 |
+12:50:03.7 |
HIP 55428 |
16.66 |
| 2026-03-26 12:00 |
11:21:08.29 |
+12:50:12.3 |
HIP 55428 |
16.77 |
| 2026-03-27 00:00 |
11:21:06.73 |
+12:50:20.9 |
HIP 55428 |
16.90 |
| 2026-03-27 12:00 |
11:21:05.18 |
+12:50:29.4 |
HIP 55428 |
17.03 |
| 2026-03-28 00:00 |
11:21:03.64 |
+12:50:37.8 |
HIP 55428 |
17.17 |
| 2026-03-28 12:00 |
11:21:02.10 |
+12:50:46.2 |
HIP 55428 |
17.32 |
| 2026-03-29 00:00 |
11:21:00.56 |
+12:50:54.5 |
HIP 55428 |
17.47 |
| 2026-03-29 12:00 |
11:20:59.03 |
+12:51:02.8 |
HIP 55428 |
17.63 |
| 2026-03-30 00:00 |
11:20:57.50 |
+12:51:11.0 |
HIP 55428 |
17.80 |
| 2026-03-30 12:00 |
11:20:55.98 |
+12:51:19.1 |
HIP 55428 |
17.97 |
| 2026-03-31 00:00 |
11:20:54.46 |
+12:51:27.2 |
HIP 55428 |
18.15 |
| 2026-03-31 12:00 |
11:20:52.95 |
+12:51:35.2 |
HIP 55428 |
18.33 |
| 2026-04-01 00:00 |
11:20:51.44 |
+12:51:43.2 |
HIP 55428 |
18.52 |
| 2026-04-01 12:00 |
11:20:49.93 |
+12:51:51.1 |
HIP 55428 |
18.71 |
| 2026-04-02 00:00 |
11:20:48.44 |
+12:51:58.9 |
HIP 55428 |
18.91 |
| 2026-04-02 12:00 |
11:20:46.94 |
+12:52:06.7 |
HIP 55428 |
19.12 |
| 2026-04-03 00:00 |
11:20:45.46 |
+12:52:14.4 |
HIP 55428 |
19.32 |
| 2026-04-03 12:00 |
11:20:43.98 |
+12:52:22.0 |
HIP 55428 |
19.53 |
| 2026-04-04 00:00 |
11:20:42.50 |
+12:52:29.6 |
HIP 55428 |
19.75 |
| 2026-04-04 12:00 |
11:20:41.03 |
+12:52:37.1 |
HIP 55428 |
19.97 |
| 2026-04-05 00:00 |
11:20:39.57 |
+12:52:44.5 |
HIP 55428 |
20.19 |
| 2026-04-05 12:00 |
11:20:38.11 |
+12:52:51.9 |
HIP 55428 |
20.42 |
| 2026-04-06 00:00 |
11:20:36.66 |
+12:52:59.2 |
HIP 55428 |
20.64 |
| 2026-04-06 12:00 |
11:20:35.21 |
+12:53:06.5 |
HIP 55428 |
20.87 |
| 2026-04-07 00:00 |
11:20:33.77 |
+12:53:13.6 |
HIP 55428 |
21.11 |
| 2026-04-07 12:00 |
11:20:32.34 |
+12:53:20.7 |
HIP 55428 |
21.34 |
| 2026-04-08 00:00 |
11:20:30.91 |
+12:53:27.8 |
HIP 55428 |
21.58 |
| 2026-04-08 12:00 |
11:20:29.49 |
+12:53:34.8 |
HIP 55428 |
21.82 |
| 2026-04-09 00:00 |
11:20:28.08 |
+12:53:41.7 |
HIP 55428 |
22.06 |
| 2026-04-09 12:00 |
11:20:26.67 |
+12:53:48.5 |
HIP 55428 |
22.30 |
| 2026-04-10 00:00 |
11:20:25.27 |
+12:53:55.2 |
HIP 55428 |
22.55 |
| 2026-04-10 12:00 |
11:20:23.88 |
+12:54:01.9 |
HIP 55428 |
22.79 |
| 2026-04-11 00:00 |
11:20:22.49 |
+12:54:08.5 |
HIP 55428 |
23.04 |
| 2026-04-11 12:00 |
11:20:21.11 |
+12:54:15.1 |
HIP 55428 |
23.29 |
| 2026-04-12 00:00 |
11:20:19.74 |
+12:54:21.6 |
HIP 55428 |
23.54 |
| 2026-04-12 12:00 |
11:20:18.38 |
+12:54:28.0 |
HIP 55428 |
23.79 |
| 2026-04-13 00:00 |
11:20:17.02 |
+12:54:34.3 |
HIP 55428 |
24.03 |
| 2026-04-13 12:00 |
11:20:15.68 |
+12:54:40.5 |
HIP 55428 |
24.28 |
| 2026-04-14 00:00 |
11:20:14.33 |
+12:54:46.7 |
HIP 55428 |
24.53 |
| 2026-04-14 12:00 |
11:20:13.00 |
+12:54:52.8 |
HIP 55428 |
24.79 |
| 2026-04-15 00:00 |
11:20:11.68 |
+12:54:58.8 |
HIP 55428 |
25.04 |
| 2026-04-15 12:00 |
11:20:10.36 |
+12:55:04.8 |
HIP 55428 |
25.29 |
| 2026-04-16 00:00 |
11:20:09.05 |
+12:55:10.7 |
HIP 55428 |
25.54 |