Interstellar mini

Job 55539682 planted 58,800 hyperbolic orbits on all 98 fields of the mini ladder and linked them with a grid whose radial velocities exceed escape. 1,558 were recovered. The orbits are drawn here.

2.6%orbits recovered, 1,558 of 58,800

0.238eligible recall, 1,558 of 6,542

54.5%detected, fewer than three paired nights

0.182real-object recall on this grid

Right ascension and declination of the 98-field mini: visits, nights that can build a tracklet, and the fields — **The 98 fields this mini shares with the others.** Same axes as the full window. Visits and paired nights are drawn only inside the cones: 1,569 square degrees, 91% of it with a visit pair on three nights or more.

What was injected

Each object is placed on the line of sight through its field, at the field's midpoint, with an excess velocity drawn from 20 to 70 km/s. The direction of that velocity is isotropic. Perihelion is kept between 0.15 and 5 AU, and in this draw it runs from 0.15 to 3.51 AU. Every orbit is hyperbolic: eccentricity 1.07 to 19.7, semi-major axis -2.22 to -0.18 AU. Apparent magnitude is uniform from 19 to 25.5, solved for at that instant, so a body at 3 AU is the same brightness as one at 1 AU. The hypothesis grid is heliohypo_iso, 270 rows from 0.5 to 4 AU with radial velocity out to 2.2 times escape. The tracklet cap on this job is 1,200 arcsec per hour. There is no second pass.

Where the orbits went

Outcome	Orbits	Share
never observable	1,907	3.2%
below depth	15,124	25.7%
lost to trailing	2,131	3.6%
depth unknown	24	0.0%
no tracklet	32,039	54.5%
no linkage	5,554	9.4%
recovered	1,558	2.6%
lost to reliability cut	463	0.8%

The median object has one paired night. The median recovered orbit has four. Once an orbit has clean tracklets on three nights inside 15 days, the remaining miss is the grid: every one of the 4,984 eligible orbits that was not recovered was never clustered.

The median on-sky rate is 213 arcsec per hour, and the 90th percentile is 562. 48,870 orbits, 83.1%, move faster than the production cap of 90 arcsec per hour. 9 exceeded this job's cap of 1,200, and none of those was recovered. The median trailing loss is 0.35, and 2,131 orbits are lost to trailing.

Distance and excess velocity

Apparent magnitude stays near 22.2 in every distance bin. Eligible recall still rises with heliocentric distance, because the slower passages both stay in the field longer and sit closer to a row of the grid.

Eligible recall against distance. The axis is percent, so 36 is a recall of 0.36. Median rate falls from about 470 arcsec per hour inside 1.5 AU to about 98 beyond 3 AU.

Distance, AU	Orbits	Recovered	Share	Eligible	Eligible recall
1–1.5	10,854	11	0.1%	224	0.049
1.5–2	20,390	94	0.5%	1,274	0.074
2–3	20,587	946	4.6%	3,652	0.259
3–5	5,062	507	10.0%	1,392	0.364

Eligible recall against excess velocity. The draw is uniform from 20 to 70 km/s, about 11,700 orbits in each bin.

Excess velocity, km/s	Orbits	Recovered	Share	Eligible	Eligible recall
20–30	11,680	612	5.2%	1,745	0.351
30–40	11,687	440	3.8%	1,575	0.279
40–50	11,788	254	2.2%	1,316	0.193
50–60	11,830	153	1.3%	1,057	0.145
60–70	11,815	99	0.8%	849	0.117

Brightness

Eligible recall stays near 0.24 from V 19 to V 23. The recovered fraction falls because fewer faint orbits ever get three nights. Fainter than V 23, 42 of 21,747 are recovered.

V	Orbits	Recovered	Share	Eligible	Eligible recall
19–21	17,588	885	5.0%	3,699	0.239
21–22	8,636	384	4.4%	1,604	0.239
22–23	8,814	238	2.7%	985	0.242
23–24	8,598	42	0.5%	210	0.200
≥24	13,149	0	0.0%	1	0.000

Inclination

An isotropic velocity puts inclination everywhere from 0 to 180 degrees, with median 90°. Prograde orbits spend more nights in the field. Retrograde orbits are linked more often once they qualify.

Inclination	Orbits	Recovered	Share	Eligible	Eligible recall
0–60°	19,445	575	3.0%	3,770	0.153
60–120°	19,963	465	2.3%	1,644	0.283
120–180°	19,392	518	2.7%	1,128	0.459

The same job on the real detections

One row from the first batch of each of the 98 fields. Real objects still mostly move under 90 arcsec per hour, and 69,248 were eligible, against 70,375 on the main-belt grid over this ladder. This grid found 12,633 of them. 54,416 of the misses were never clustered. Of 63,689 linkages, 50,732 are pure, 31 are mixed (0.049%), and 12,926 are unlabelled (20.3%). On this ladder the main-belt grid recovered 0.827 of eligible real objects, with 0.31% mixed.

Source: the field tables in output/linking/swarm_map_iso-mini, job 55539682. Angles on the orbits page were redrawn from the injection seed and checked against the stored elements.