C/1968 L1 (Whitaker-Thomas)
| 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 |
-0.500 |
| 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) |
| 2026-02-03 00:00 |
03:52:50.12 |
+38:15:43.7 |
HIP 18240 |
21.63 |
| 2026-02-03 12:00 |
03:52:49.62 |
+38:15:35.7 |
HIP 18240 |
21.79 |
| 2026-02-04 00:00 |
03:52:49.14 |
+38:15:27.7 |
HIP 18240 |
21.96 |
| 2026-02-04 12:00 |
03:52:48.67 |
+38:15:19.7 |
HIP 18240 |
22.12 |
| 2026-02-05 00:00 |
03:52:48.22 |
+38:15:11.8 |
HIP 18240 |
22.27 |
| 2026-02-05 12:00 |
03:52:47.79 |
+38:15:03.8 |
HIP 18240 |
22.43 |
| 2026-02-06 00:00 |
03:52:47.37 |
+38:14:55.9 |
HIP 18240 |
22.58 |
| 2026-02-06 12:00 |
03:52:46.96 |
+38:14:48.0 |
HIP 18240 |
22.73 |
| 2026-02-07 00:00 |
03:52:46.57 |
+38:14:40.2 |
HIP 18240 |
22.88 |
| 2026-02-07 12:00 |
03:52:46.20 |
+38:14:32.3 |
HIP 18240 |
23.03 |
| 2026-02-08 00:00 |
03:52:45.84 |
+38:14:24.5 |
HIP 18240 |
23.17 |
| 2026-02-08 12:00 |
03:52:45.49 |
+38:14:16.8 |
HIP 18240 |
23.31 |
| 2026-02-09 00:00 |
03:52:45.17 |
+38:14:09.0 |
HIP 18240 |
23.45 |
| 2026-02-09 12:00 |
03:52:44.86 |
+38:14:01.3 |
HIP 18240 |
23.59 |
| 2026-02-10 00:00 |
03:52:44.56 |
+38:13:53.6 |
HIP 18240 |
23.72 |
| 2026-02-10 12:00 |
03:52:44.28 |
+38:13:45.9 |
HIP 18240 |
23.85 |
| 2026-02-11 00:00 |
03:52:44.01 |
+38:13:38.3 |
HIP 18240 |
23.98 |
| 2026-02-11 12:00 |
03:52:43.76 |
+38:13:30.7 |
HIP 18240 |
24.11 |
| 2026-02-12 00:00 |
03:52:43.53 |
+38:13:23.1 |
HIP 18240 |
24.24 |
| 2026-02-12 12:00 |
03:52:43.31 |
+38:13:15.6 |
HIP 18240 |
24.36 |
| 2026-02-13 00:00 |
03:52:43.11 |
+38:13:08.0 |
HIP 18240 |
24.48 |
| 2026-02-13 12:00 |
03:52:42.92 |
+38:13:00.6 |
HIP 18240 |
24.60 |
| 2026-02-14 00:00 |
03:52:42.75 |
+38:12:53.1 |
HIP 18240 |
24.71 |
| 2026-02-14 12:00 |
03:52:42.60 |
+38:12:45.7 |
HIP 18240 |
24.83 |
| 2026-02-15 00:00 |
03:52:42.46 |
+38:12:38.3 |
HIP 18240 |
24.94 |
| 2026-02-15 12:00 |
03:52:42.33 |
+38:12:31.0 |
HIP 18240 |
25.05 |
| 2026-02-16 00:00 |
03:52:42.23 |
+38:12:23.7 |
HIP 18240 |
25.16 |
| 2026-02-16 12:00 |
03:52:42.13 |
+38:12:16.4 |
HIP 18240 |
25.26 |
| 2026-02-17 00:00 |
03:52:42.06 |
+38:12:09.2 |
HIP 18240 |
25.36 |
| 2026-02-17 12:00 |
03:52:42.00 |
+38:12:02.0 |
HIP 18240 |
25.46 |
| 2026-02-18 00:00 |
03:52:41.95 |
+38:11:54.8 |
HIP 18240 |
25.56 |
| 2026-02-18 12:00 |
03:52:41.92 |
+38:11:47.7 |
HIP 18240 |
25.65 |
| 2026-02-19 00:00 |
03:52:41.91 |
+38:11:40.6 |
HIP 18240 |
25.75 |
| 2026-02-19 12:00 |
03:52:41.91 |
+38:11:33.6 |
HIP 18240 |
25.84 |
| 2026-02-20 00:00 |
03:52:41.93 |
+38:11:26.6 |
HIP 18240 |
25.93 |
| 2026-02-20 12:00 |
03:52:41.96 |
+38:11:19.6 |
HIP 18240 |
26.01 |
| 2026-02-21 00:00 |
03:52:42.01 |
+38:11:12.7 |
HIP 18240 |
26.10 |
| 2026-02-21 12:00 |
03:52:42.08 |
+38:11:05.8 |
HIP 18240 |
26.18 |
| 2026-02-22 00:00 |
03:52:42.16 |
+38:10:58.9 |
HIP 18240 |
26.26 |
| 2026-02-22 12:00 |
03:52:42.26 |
+38:10:52.1 |
HIP 18240 |
26.34 |
| 2026-02-23 00:00 |
03:52:42.37 |
+38:10:45.4 |
HIP 18240 |
26.41 |
| 2026-02-23 12:00 |
03:52:42.50 |
+38:10:38.7 |
HIP 18240 |
26.48 |
| 2026-02-24 00:00 |
03:52:42.64 |
+38:10:32.0 |
HIP 18240 |
26.56 |