C/1972 F1 (Gehrels)
| Parameter |
Value |
| Designation |
C/1972 F1 (Gehrels) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1971-01-06T12:19:44.146560Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:19Z |
| Obs used |
18 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1972-08-05.0000000 |
| e |
0.99788599 |
| q (au) |
3.276471 |
| a (au) |
1549.882081 |
| i (deg) |
175.610745 |
| Ω (om, deg) |
24.754752 |
| ω (w, deg) |
128.702717 |
| M (ma, deg) |
0.009312 |
Magnitude
Scatter + Global Linear
$$
M_a = (8.957 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
8.957 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.900 |
| k |
0.800 |
| 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 |
06:37:56.35 |
+18:52:11.7 |
HIP 31713 |
18.77 |
| 2026-02-03 12:00 |
06:37:54.95 |
+18:52:14.1 |
HIP 31713 |
18.83 |
| 2026-02-04 00:00 |
06:37:53.56 |
+18:52:16.4 |
HIP 31713 |
18.90 |
| 2026-02-04 12:00 |
06:37:52.18 |
+18:52:18.7 |
HIP 31713 |
18.97 |
| 2026-02-05 00:00 |
06:37:50.80 |
+18:52:21.0 |
HIP 31713 |
19.05 |
| 2026-02-05 12:00 |
06:37:49.44 |
+18:52:23.4 |
HIP 31713 |
19.13 |
| 2026-02-06 00:00 |
06:37:48.08 |
+18:52:25.7 |
HIP 31713 |
19.21 |
| 2026-02-06 12:00 |
06:37:46.73 |
+18:52:28.0 |
HIP 31713 |
19.30 |
| 2026-02-07 00:00 |
06:37:45.39 |
+18:52:30.4 |
HIP 31713 |
19.40 |
| 2026-02-07 12:00 |
06:37:44.06 |
+18:52:32.7 |
HIP 31713 |
19.50 |
| 2026-02-08 00:00 |
06:37:42.74 |
+18:52:35.1 |
HIP 31618 |
19.56 |
| 2026-02-08 12:00 |
06:37:41.43 |
+18:52:37.4 |
HIP 31618 |
19.38 |
| 2026-02-09 00:00 |
06:37:40.13 |
+18:52:39.8 |
HIP 31618 |
19.20 |
| 2026-02-09 12:00 |
06:37:38.84 |
+18:52:42.1 |
HIP 31618 |
19.02 |
| 2026-02-10 00:00 |
06:37:37.56 |
+18:52:44.5 |
HIP 31618 |
18.85 |
| 2026-02-10 12:00 |
06:37:36.28 |
+18:52:46.8 |
HIP 31618 |
18.68 |
| 2026-02-11 00:00 |
06:37:35.02 |
+18:52:49.2 |
HIP 31618 |
18.52 |
| 2026-02-11 12:00 |
06:37:33.77 |
+18:52:51.5 |
HIP 31618 |
18.36 |
| 2026-02-12 00:00 |
06:37:32.52 |
+18:52:53.9 |
HIP 31618 |
18.20 |
| 2026-02-12 12:00 |
06:37:31.29 |
+18:52:56.2 |
HIP 31618 |
18.05 |
| 2026-02-13 00:00 |
06:37:30.07 |
+18:52:58.6 |
HIP 31618 |
17.91 |
| 2026-02-13 12:00 |
06:37:28.86 |
+18:53:01.0 |
HIP 31618 |
17.77 |
| 2026-02-14 00:00 |
06:37:27.66 |
+18:53:03.3 |
HIP 31618 |
17.63 |
| 2026-02-14 12:00 |
06:37:26.47 |
+18:53:05.7 |
HIP 31618 |
17.50 |
| 2026-02-15 00:00 |
06:37:25.29 |
+18:53:08.0 |
HIP 31618 |
17.37 |
| 2026-02-15 12:00 |
06:37:24.12 |
+18:53:10.4 |
HIP 31618 |
17.25 |
| 2026-02-16 00:00 |
06:37:22.96 |
+18:53:12.8 |
HIP 31618 |
17.13 |
| 2026-02-16 12:00 |
06:37:21.81 |
+18:53:15.1 |
HIP 31618 |
17.02 |
| 2026-02-17 00:00 |
06:37:20.67 |
+18:53:17.5 |
HIP 31618 |
16.91 |
| 2026-02-17 12:00 |
06:37:19.55 |
+18:53:19.8 |
HIP 31618 |
16.80 |
| 2026-02-18 00:00 |
06:37:18.44 |
+18:53:22.2 |
HIP 31618 |
16.70 |
| 2026-02-18 12:00 |
06:37:17.33 |
+18:53:24.5 |
HIP 31618 |
16.60 |
| 2026-02-19 00:00 |
06:37:16.24 |
+18:53:26.9 |
HIP 31618 |
16.51 |
| 2026-02-19 12:00 |
06:37:15.16 |
+18:53:29.2 |
HIP 31618 |
16.42 |
| 2026-02-20 00:00 |
06:37:14.09 |
+18:53:31.6 |
HIP 31618 |
16.34 |
| 2026-02-20 12:00 |
06:37:13.03 |
+18:53:33.9 |
HIP 31618 |
16.26 |
| 2026-02-21 00:00 |
06:37:11.99 |
+18:53:36.3 |
HIP 31618 |
16.18 |
| 2026-02-21 12:00 |
06:37:10.96 |
+18:53:38.6 |
HIP 31618 |
16.11 |
| 2026-02-22 00:00 |
06:37:09.93 |
+18:53:41.0 |
HIP 31618 |
16.04 |
| 2026-02-22 12:00 |
06:37:08.92 |
+18:53:43.3 |
HIP 31618 |
15.97 |
| 2026-02-23 00:00 |
06:37:07.92 |
+18:53:45.6 |
HIP 31618 |
15.91 |
| 2026-02-23 12:00 |
06:37:06.94 |
+18:53:48.0 |
HIP 31618 |
15.86 |
| 2026-02-24 00:00 |
06:37:05.96 |
+18:53:50.3 |
HIP 31618 |
15.80 |