C/1913 Y1 (Delavan)
| Parameter |
Value |
| Designation |
C/1913 Y1 (Delavan) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1914-10-26T18:27:07.724160Z |
| Orbit solution date (soln_date, UTC) |
2024-04-15T15:43:28Z |
| Obs used |
157 |
| NEO |
- |
| M1 |
4.800 |
| K1 |
4.250 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1914-03-15.0000000 |
| e |
1.00014579 |
| q (au) |
1.104401 |
| a (au) |
-7575.468577 |
| i (deg) |
68.042932 |
| Ω (om, deg) |
60.397252 |
| ω (w, deg) |
97.469440 |
| M (ma, deg) |
-0.000337 |
Magnitude
Scatter + Global Linear
$$
M_a = (-2.437 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
-2.437 |
| n |
6.000 |
| 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 |
01:44:48.90 |
-70:18:23.5 |
HIP 8394 |
22.78 |
| 2026-02-03 12:00 |
01:44:49.59 |
-70:18:09.9 |
HIP 8394 |
22.59 |
| 2026-02-04 00:00 |
01:44:50.31 |
-70:17:56.3 |
HIP 8394 |
22.41 |
| 2026-02-04 12:00 |
01:44:51.06 |
-70:17:42.8 |
HIP 8394 |
22.22 |
| 2026-02-05 00:00 |
01:44:51.82 |
-70:17:29.3 |
HIP 8394 |
22.03 |
| 2026-02-05 12:00 |
01:44:52.60 |
-70:17:15.8 |
HIP 8394 |
21.85 |
| 2026-02-06 00:00 |
01:44:53.40 |
-70:17:02.4 |
HIP 8394 |
21.66 |
| 2026-02-06 12:00 |
01:44:54.23 |
-70:16:49.0 |
HIP 8394 |
21.47 |
| 2026-02-07 00:00 |
01:44:55.07 |
-70:16:35.6 |
HIP 8394 |
21.28 |
| 2026-02-07 12:00 |
01:44:55.94 |
-70:16:22.2 |
HIP 8394 |
21.10 |
| 2026-02-08 00:00 |
01:44:56.83 |
-70:16:08.9 |
HIP 8394 |
20.91 |
| 2026-02-08 12:00 |
01:44:57.74 |
-70:15:55.6 |
HIP 8394 |
20.72 |
| 2026-02-09 00:00 |
01:44:58.66 |
-70:15:42.4 |
HIP 8394 |
20.53 |
| 2026-02-09 12:00 |
01:44:59.61 |
-70:15:29.2 |
HIP 8394 |
20.34 |
| 2026-02-10 00:00 |
01:45:00.58 |
-70:15:16.0 |
HIP 8394 |
20.15 |
| 2026-02-10 12:00 |
01:45:01.57 |
-70:15:02.9 |
HIP 8394 |
19.97 |
| 2026-02-11 00:00 |
01:45:02.58 |
-70:14:49.8 |
HIP 8394 |
19.78 |
| 2026-02-11 12:00 |
01:45:03.61 |
-70:14:36.8 |
HIP 8394 |
19.59 |
| 2026-02-12 00:00 |
01:45:04.66 |
-70:14:23.8 |
HIP 8394 |
19.40 |
| 2026-02-12 12:00 |
01:45:05.73 |
-70:14:10.8 |
HIP 8394 |
19.21 |
| 2026-02-13 00:00 |
01:45:06.82 |
-70:13:57.9 |
HIP 8394 |
19.02 |
| 2026-02-13 12:00 |
01:45:07.93 |
-70:13:45.0 |
HIP 8394 |
18.83 |
| 2026-02-14 00:00 |
01:45:09.06 |
-70:13:32.2 |
HIP 8394 |
18.64 |
| 2026-02-14 12:00 |
01:45:10.21 |
-70:13:19.4 |
HIP 8394 |
18.45 |
| 2026-02-15 00:00 |
01:45:11.38 |
-70:13:06.7 |
HIP 8394 |
18.26 |
| 2026-02-15 12:00 |
01:45:12.56 |
-70:12:54.0 |
HIP 8394 |
18.07 |
| 2026-02-16 00:00 |
01:45:13.77 |
-70:12:41.4 |
HIP 8394 |
17.88 |
| 2026-02-16 12:00 |
01:45:15.00 |
-70:12:28.8 |
HIP 8394 |
17.69 |
| 2026-02-17 00:00 |
01:45:16.24 |
-70:12:16.3 |
HIP 8394 |
17.50 |
| 2026-02-17 12:00 |
01:45:17.51 |
-70:12:03.8 |
HIP 8394 |
17.31 |
| 2026-02-18 00:00 |
01:45:18.79 |
-70:11:51.4 |
HIP 8394 |
17.12 |
| 2026-02-18 12:00 |
01:45:20.09 |
-70:11:39.0 |
HIP 8394 |
16.93 |
| 2026-02-19 00:00 |
01:45:21.41 |
-70:11:26.7 |
HIP 8394 |
16.74 |
| 2026-02-19 12:00 |
01:45:22.75 |
-70:11:14.4 |
HIP 8394 |
16.55 |
| 2026-02-20 00:00 |
01:45:24.11 |
-70:11:02.2 |
HIP 8394 |
16.36 |
| 2026-02-20 12:00 |
01:45:25.48 |
-70:10:50.1 |
HIP 8394 |
16.18 |
| 2026-02-21 00:00 |
01:45:26.88 |
-70:10:38.0 |
HIP 8394 |
15.99 |
| 2026-02-21 12:00 |
01:45:28.29 |
-70:10:26.0 |
HIP 8394 |
15.80 |
| 2026-02-22 00:00 |
01:45:29.72 |
-70:10:14.0 |
HIP 8394 |
15.61 |
| 2026-02-22 12:00 |
01:45:31.17 |
-70:10:02.2 |
HIP 8394 |
15.42 |
| 2026-02-23 00:00 |
01:45:32.63 |
-70:09:50.3 |
HIP 8394 |
15.23 |
| 2026-02-23 12:00 |
01:45:34.11 |
-70:09:38.6 |
HIP 8394 |
15.04 |
| 2026-02-24 00:00 |
01:45:35.61 |
-70:09:26.9 |
HIP 8394 |
14.85 |