C/1995 Q2 (Hartley-Drinkwater)
| Parameter |
Value |
| Designation |
C/1995 Q2 (Hartley-Drinkwater) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1995-08-02T17:27:23.549760Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:47Z |
| Obs used |
123 |
| NEO |
- |
| M1 |
9.700 |
| K1 |
22.000 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1995-09-06.0000000 |
| e |
0.96649288 |
| q (au) |
1.889143 |
| a (au) |
56.380355 |
| i (deg) |
168.007513 |
| Ω (om, deg) |
300.750783 |
| ω (w, deg) |
314.000279 |
| M (ma, deg) |
0.079792 |
Magnitude
Scatter + Global Linear
$$
M_a = (13.337 + 4.533\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
13.337 |
| n |
4.533 |
| gf |
0.995 |
| gb |
-0.557 |
| k |
0.869 |
| δ90 |
9.997 |
| 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 |
12:34:54.08 |
+08:02:42.8 |
HIP 61366 |
19.50 |
| 2026-02-03 12:00 |
12:34:52.65 |
+08:02:58.1 |
HIP 61366 |
19.64 |
| 2026-02-04 00:00 |
12:34:51.20 |
+08:03:13.4 |
HIP 61366 |
19.79 |
| 2026-02-04 12:00 |
12:34:49.73 |
+08:03:28.8 |
HIP 61366 |
19.95 |
| 2026-02-05 00:00 |
12:34:48.24 |
+08:03:44.3 |
HIP 61366 |
20.12 |
| 2026-02-05 12:00 |
12:34:46.74 |
+08:03:59.9 |
HIP 61366 |
20.30 |
| 2026-02-06 00:00 |
12:34:45.21 |
+08:04:15.5 |
HIP 61366 |
20.49 |
| 2026-02-06 12:00 |
12:34:43.68 |
+08:04:31.2 |
HIP 61366 |
20.68 |
| 2026-02-07 00:00 |
12:34:42.12 |
+08:04:46.9 |
HIP 61273 |
20.79 |
| 2026-02-07 12:00 |
12:34:40.55 |
+08:05:02.8 |
HIP 61273 |
20.54 |
| 2026-02-08 00:00 |
12:34:38.96 |
+08:05:18.6 |
HIP 61273 |
20.29 |
| 2026-02-08 12:00 |
12:34:37.36 |
+08:05:34.6 |
HIP 61273 |
20.05 |
| 2026-02-09 00:00 |
12:34:35.74 |
+08:05:50.5 |
HIP 61273 |
19.81 |
| 2026-02-09 12:00 |
12:34:34.10 |
+08:06:06.6 |
HIP 61273 |
19.57 |
| 2026-02-10 00:00 |
12:34:32.45 |
+08:06:22.7 |
HIP 61273 |
19.35 |
| 2026-02-10 12:00 |
12:34:30.78 |
+08:06:38.8 |
HIP 61273 |
19.13 |
| 2026-02-11 00:00 |
12:34:29.10 |
+08:06:55.1 |
HIP 61273 |
18.91 |
| 2026-02-11 12:00 |
12:34:27.40 |
+08:07:11.3 |
HIP 61273 |
18.71 |
| 2026-02-12 00:00 |
12:34:25.68 |
+08:07:27.6 |
HIP 61273 |
18.51 |
| 2026-02-12 12:00 |
12:34:23.95 |
+08:07:44.0 |
HIP 61273 |
18.33 |
| 2026-02-13 00:00 |
12:34:22.20 |
+08:08:00.4 |
HIP 61273 |
18.15 |
| 2026-02-13 12:00 |
12:34:20.44 |
+08:08:16.9 |
HIP 61273 |
17.99 |
| 2026-02-14 00:00 |
12:34:18.67 |
+08:08:33.4 |
HIP 61273 |
17.83 |
| 2026-02-14 12:00 |
12:34:16.87 |
+08:08:49.9 |
HIP 61273 |
17.69 |
| 2026-02-15 00:00 |
12:34:15.07 |
+08:09:06.5 |
HIP 61273 |
17.56 |
| 2026-02-15 12:00 |
12:34:13.25 |
+08:09:23.1 |
HIP 61273 |
17.44 |
| 2026-02-16 00:00 |
12:34:11.41 |
+08:09:39.8 |
HIP 61273 |
17.33 |
| 2026-02-16 12:00 |
12:34:09.56 |
+08:09:56.5 |
HIP 61273 |
17.24 |
| 2026-02-17 00:00 |
12:34:07.69 |
+08:10:13.3 |
HIP 61273 |
17.17 |
| 2026-02-17 12:00 |
12:34:05.82 |
+08:10:30.1 |
HIP 61273 |
17.10 |
| 2026-02-18 00:00 |
12:34:03.92 |
+08:10:46.9 |
HIP 61273 |
17.06 |
| 2026-02-18 12:00 |
12:34:02.02 |
+08:11:03.7 |
HIP 61273 |
17.03 |
| 2026-02-19 00:00 |
12:34:00.10 |
+08:11:20.6 |
HIP 61273 |
17.02 |
| 2026-02-19 12:00 |
12:33:58.16 |
+08:11:37.5 |
HIP 61273 |
17.02 |
| 2026-02-20 00:00 |
12:33:56.22 |
+08:11:54.5 |
HIP 61273 |
17.04 |
| 2026-02-20 12:00 |
12:33:54.26 |
+08:12:11.5 |
HIP 61273 |
17.08 |
| 2026-02-21 00:00 |
12:33:52.28 |
+08:12:28.5 |
HIP 61273 |
17.13 |
| 2026-02-21 12:00 |
12:33:50.30 |
+08:12:45.5 |
HIP 61273 |
17.21 |
| 2026-02-22 00:00 |
12:33:48.30 |
+08:13:02.5 |
HIP 61273 |
17.30 |
| 2026-02-22 12:00 |
12:33:46.29 |
+08:13:19.6 |
HIP 61273 |
17.40 |
| 2026-02-23 00:00 |
12:33:44.26 |
+08:13:36.7 |
HIP 61273 |
17.53 |
| 2026-02-23 12:00 |
12:33:42.23 |
+08:13:53.8 |
HIP 61273 |
17.67 |
| 2026-02-24 00:00 |
12:33:40.18 |
+08:14:10.9 |
HIP 61273 |
17.83 |