| Parameter |
Value |
| Designation |
C/1968 L1 (Whitaker-Thomas) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1968-06-04T12:06:59.990400Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:17Z |
| Obs used |
23 |
| NEO |
- |
| M1 |
11.900 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1968-07-02.0000000 |
| e |
1.00000000 |
| q (au) |
1.234006 |
| a (au) |
- |
| i (deg) |
61.767368 |
| Ω (om, deg) |
254.716109 |
| ω (w, deg) |
353.977969 |
| M (ma, deg) |
- |
Magnitude
Scatter + Global Linear
$$
M_a = (9.895 + 3.317\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.895 |
| n |
3.317 |
| 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) |
| 2026-06-01 00:00 |
03:56:43.67 |
+38:07:14.5 |
HIP 18358 |
18.48 |
| 2026-06-01 12:00 |
03:56:45.40 |
+38:07:19.2 |
HIP 18358 |
18.70 |
| 2026-06-02 00:00 |
03:56:47.13 |
+38:07:23.9 |
HIP 18358 |
18.92 |
| 2026-06-02 12:00 |
03:56:48.86 |
+38:07:28.6 |
HIP 18358 |
19.14 |
| 2026-06-03 00:00 |
03:56:50.58 |
+38:07:33.4 |
HIP 18358 |
19.37 |
| 2026-06-03 12:00 |
03:56:52.30 |
+38:07:38.2 |
HIP 18358 |
19.60 |
| 2026-06-04 00:00 |
03:56:54.02 |
+38:07:43.1 |
HIP 18358 |
19.83 |
| 2026-06-04 12:00 |
03:56:55.73 |
+38:07:48.0 |
HIP 18358 |
20.07 |
| 2026-06-05 00:00 |
03:56:57.44 |
+38:07:53.0 |
HIP 18358 |
20.30 |
| 2026-06-05 12:00 |
03:56:59.15 |
+38:07:58.0 |
HIP 18358 |
20.54 |
| 2026-06-06 00:00 |
03:57:00.86 |
+38:08:03.1 |
HIP 18358 |
20.78 |
| 2026-06-06 12:00 |
03:57:02.56 |
+38:08:08.2 |
HIP 18358 |
21.02 |
| 2026-06-07 00:00 |
03:57:04.26 |
+38:08:13.3 |
HIP 18358 |
21.27 |
| 2026-06-07 12:00 |
03:57:05.95 |
+38:08:18.5 |
HIP 18358 |
21.52 |
| 2026-06-08 00:00 |
03:57:07.65 |
+38:08:23.7 |
HIP 18358 |
21.76 |
| 2026-06-08 12:00 |
03:57:09.33 |
+38:08:29.0 |
HIP 18358 |
22.01 |
| 2026-06-09 00:00 |
03:57:11.02 |
+38:08:34.3 |
HIP 18358 |
22.26 |
| 2026-06-09 12:00 |
03:57:12.70 |
+38:08:39.6 |
HIP 18358 |
22.52 |
| 2026-06-10 00:00 |
03:57:14.37 |
+38:08:45.0 |
HIP 18358 |
22.77 |
| 2026-06-10 12:00 |
03:57:16.04 |
+38:08:50.4 |
HIP 18358 |
23.03 |
| 2026-06-11 00:00 |
03:57:17.71 |
+38:08:55.9 |
HIP 18358 |
23.28 |
| 2026-06-11 12:00 |
03:57:19.37 |
+38:09:01.4 |
HIP 18358 |
23.54 |
| 2026-06-12 00:00 |
03:57:21.03 |
+38:09:07.0 |
HIP 18358 |
23.80 |
| 2026-06-12 12:00 |
03:57:22.69 |
+38:09:12.5 |
HIP 18358 |
24.06 |
| 2026-06-13 00:00 |
03:57:24.34 |
+38:09:18.2 |
HIP 18628 |
24.24 |
| 2026-06-13 12:00 |
03:57:25.98 |
+38:09:23.8 |
HIP 18628 |
24.00 |
| 2026-06-14 00:00 |
03:57:27.62 |
+38:09:29.5 |
HIP 18628 |
23.76 |
| 2026-06-14 12:00 |
03:57:29.25 |
+38:09:35.2 |
HIP 18628 |
23.53 |
| 2026-06-15 00:00 |
03:57:30.88 |
+38:09:41.0 |
HIP 18628 |
23.30 |
| 2026-06-15 12:00 |
03:57:32.50 |
+38:09:46.8 |
HIP 18628 |
23.07 |
| 2026-06-16 00:00 |
03:57:34.12 |
+38:09:52.7 |
HIP 18628 |
22.85 |
| 2026-06-16 12:00 |
03:57:35.73 |
+38:09:58.5 |
HIP 18628 |
22.63 |
| 2026-06-17 00:00 |
03:57:37.34 |
+38:10:04.4 |
HIP 18628 |
22.42 |
| 2026-06-17 12:00 |
03:57:38.94 |
+38:10:10.4 |
HIP 18628 |
22.21 |
| 2026-06-18 00:00 |
03:57:40.53 |
+38:10:16.4 |
HIP 18628 |
22.00 |
| 2026-06-18 12:00 |
03:57:42.12 |
+38:10:22.4 |
HIP 18628 |
21.80 |
| 2026-06-19 00:00 |
03:57:43.70 |
+38:10:28.4 |
HIP 18628 |
21.61 |
| 2026-06-19 12:00 |
03:57:45.28 |
+38:10:34.5 |
HIP 18628 |
21.41 |
| 2026-06-20 00:00 |
03:57:46.85 |
+38:10:40.6 |
HIP 18628 |
21.23 |
| 2026-06-20 12:00 |
03:57:48.41 |
+38:10:46.7 |
HIP 18628 |
21.05 |
| 2026-06-21 00:00 |
03:57:49.97 |
+38:10:52.9 |
HIP 18628 |
20.87 |
| 2026-06-21 12:00 |
03:57:51.52 |
+38:10:59.1 |
HIP 18628 |
20.69 |
| 2026-06-22 00:00 |
03:57:53.06 |
+38:11:05.3 |
HIP 18628 |
20.53 |