C/1970 N1 (Abe)
| Parameter |
Value |
| Designation |
C/1970 N1 (Abe) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1970-10-20T16:46:43.086720Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:19Z |
| Obs used |
271 |
| NEO |
- |
| M1 |
6.600 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1970-10-11.0000000 |
| e |
1.00003692 |
| q (au) |
1.112541 |
| a (au) |
-30136.217151 |
| i (deg) |
126.719910 |
| Ω (om, deg) |
21.701358 |
| ω (w, deg) |
96.583364 |
| M (ma, deg) |
-0.000002 |
Magnitude
Scatter + Global Linear
$$
M_a = (5.447 + 3.246\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
5.447 |
| n |
3.246 |
| gf |
0.800 |
| gb |
-0.948 |
| k |
0.999 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 1970-07-05 |
1970-10-20 |
+1.2370 |
-0.055 |
| 1970-10-20 |
1971-03-07 |
-0.0609 |
-0.277 |
| 1971-03-07 |
1971-05-25 |
+5.0362 |
-1.623 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
07:30:45.42 |
-32:23:14.8 |
HIP 36459 |
8.42 |
| 2026-02-03 12:00 |
07:30:43.76 |
-32:23:05.8 |
HIP 36459 |
8.04 |
| 2026-02-04 00:00 |
07:30:42.11 |
-32:22:56.7 |
HIP 36459 |
7.66 |
| 2026-02-04 12:00 |
07:30:40.47 |
-32:22:47.5 |
HIP 36459 |
7.29 |
| 2026-02-05 00:00 |
07:30:38.84 |
-32:22:38.1 |
HIP 36459 |
6.91 |
| 2026-02-05 12:00 |
07:30:37.21 |
-32:22:28.6 |
HIP 36459 |
6.54 |
| 2026-02-06 00:00 |
07:30:35.58 |
-32:22:19.0 |
HIP 36459 |
6.16 |
| 2026-02-06 12:00 |
07:30:33.97 |
-32:22:09.2 |
HIP 36459 |
5.79 |
| 2026-02-07 00:00 |
07:30:32.36 |
-32:21:59.2 |
HIP 36459 |
5.42 |
| 2026-02-07 12:00 |
07:30:30.76 |
-32:21:49.2 |
HIP 36459 |
5.05 |
| 2026-02-08 00:00 |
07:30:29.17 |
-32:21:39.0 |
HIP 36459 |
4.69 |
| 2026-02-08 12:00 |
07:30:27.58 |
-32:21:28.7 |
HIP 36459 |
4.33 |
| 2026-02-09 00:00 |
07:30:26.00 |
-32:21:18.2 |
HIP 36459 |
3.97 |
| 2026-02-09 12:00 |
07:30:24.43 |
-32:21:07.6 |
HIP 36459 |
3.61 |
| 2026-02-10 00:00 |
07:30:22.86 |
-32:20:56.9 |
HIP 36459 |
3.27 |
| 2026-02-10 12:00 |
07:30:21.31 |
-32:20:46.1 |
HIP 36459 |
2.93 |
| 2026-02-11 00:00 |
07:30:19.76 |
-32:20:35.1 |
HIP 36459 |
2.60 |
| 2026-02-11 12:00 |
07:30:18.22 |
-32:20:24.0 |
HIP 36459 |
2.29 |
| 2026-02-12 00:00 |
07:30:16.69 |
-32:20:12.7 |
HIP 36459 |
2.01 |
| 2026-02-12 12:00 |
07:30:15.16 |
-32:20:01.4 |
HIP 36459 |
1.76 |
| 2026-02-13 00:00 |
07:30:13.65 |
-32:19:49.9 |
HIP 36459 |
1.56 |
| 2026-02-13 12:00 |
07:30:12.14 |
-32:19:38.3 |
HIP 36459 |
1.44 |
| 2026-02-14 00:00 |
07:30:10.64 |
-32:19:26.5 |
HIP 36459 |
1.41 |
| 2026-02-14 12:00 |
07:30:09.15 |
-32:19:14.7 |
HIP 36459 |
1.48 |
| 2026-02-15 00:00 |
07:30:07.67 |
-32:19:02.7 |
HIP 36459 |
1.64 |
| 2026-02-15 12:00 |
07:30:06.20 |
-32:18:50.6 |
HIP 36459 |
1.86 |
| 2026-02-16 00:00 |
07:30:04.74 |
-32:18:38.4 |
HIP 36459 |
2.12 |
| 2026-02-16 12:00 |
07:30:03.28 |
-32:18:26.0 |
HIP 36459 |
2.41 |
| 2026-02-17 00:00 |
07:30:01.84 |
-32:18:13.6 |
HIP 36459 |
2.73 |
| 2026-02-17 12:00 |
07:30:00.41 |
-32:18:01.0 |
HIP 36459 |
3.05 |
| 2026-02-18 00:00 |
07:29:58.98 |
-32:17:48.3 |
HIP 36459 |
3.39 |
| 2026-02-18 12:00 |
07:29:57.57 |
-32:17:35.5 |
HIP 36459 |
3.73 |
| 2026-02-19 00:00 |
07:29:56.16 |
-32:17:22.6 |
HIP 36459 |
4.07 |
| 2026-02-19 12:00 |
07:29:54.77 |
-32:17:09.6 |
HIP 36459 |
4.42 |
| 2026-02-20 00:00 |
07:29:53.38 |
-32:16:56.4 |
HIP 36459 |
4.78 |
| 2026-02-20 12:00 |
07:29:52.01 |
-32:16:43.2 |
HIP 36459 |
5.13 |
| 2026-02-21 00:00 |
07:29:50.64 |
-32:16:29.8 |
HIP 36459 |
5.49 |
| 2026-02-21 12:00 |
07:29:49.29 |
-32:16:16.4 |
HIP 36459 |
5.84 |
| 2026-02-22 00:00 |
07:29:47.94 |
-32:16:02.8 |
HIP 36459 |
6.20 |
| 2026-02-22 12:00 |
07:29:46.61 |
-32:15:49.1 |
HIP 36459 |
6.56 |
| 2026-02-23 00:00 |
07:29:45.29 |
-32:15:35.4 |
HIP 36459 |
6.92 |
| 2026-02-23 12:00 |
07:29:43.98 |
-32:15:21.5 |
HIP 36459 |
7.28 |
| 2026-02-24 00:00 |
07:29:42.67 |
-32:15:07.5 |
HIP 36459 |
7.63 |