Transit Planner · LCO network · 40 cm telescopes

Which exoplanet to image now

One click returns the best planets from this moment on, and for each one you pick — time windows ready to enter by hand in LCO. Every window is checked to be fully observable, padding included, from a site that has a 40 cm telescope.

Network sites with a 40 cm telescope

Wise Observatory is not on the list — it has a 1 m telescope only. Ali Observatory is still being built and has no active telescopes.

Parameters

Search ahead (days)

Minimum lead time (hours)

Padding before and after (min)

Minimum sites per window

Maximum magnitude

Minimum transit depth (%)

Maximum transit duration (hours)

Maximum timing uncertainty (min)

Minimum altitude (°)

Darkness required

Sort candidates by

Minimum windows per planet

How many candidates to show

Two of the defaults here differ from the eclipsing-binary tool, on purpose. The minimum number of windows is 3, not 10, because orbital periods are far longer and only some transits fall in darkness and above the horizon. And the minimum number of sites is 1, because a padded transit window runs two and a half to four and a half hours and so almost never fits entirely inside the dark window of two sites at once — requiring two sites drops the candidate count from 56 to 2.

Candidates to image

Planet	Mag	Transit depth	Duration	Period (days)	Next transit UTC	In	Sites for that one	Windows in range	Uncertainty

Time windows to enter in LCO

#	Window start UTC	Window end UTC	Length	Mid transit UTC	In	Sites that can do it

Copy — every window, tab separated

Building an LCO request

The windows in the table go into the request as they are. You set the exposure time — the number of exposures, the block length, the cadence and the baseline all follow from it and from the window length. The target in the request is the host star, not the planet.

Request name prefix (optional)

LCO proposal code

Exposure time (seconds)

Padding (min)

Requested cadence (min)

Filter

Proper motion RA

Proper motion Dec

Parallax (blank = skip)

Coordinate epoch

Defocus (mm)

Only v and rp have actually been verified against the portal. For a red dwarf rp is much the better choice.

The epoch trap. As long as the proper motion is zero, the epoch field changes nothing. The moment you fill it in, LCO rolls the position forward from the epoch you declared — so it has to match the coordinates. The coordinates in the catalogue here are not necessarily J2000: those of HIP 65 A, for example, are epoch 2015.5, and differ from J2000 by 3.3 arcseconds. If you take a proper motion from SIMBAD, take the coordinates and their epoch from there too.