# The DECam Minute Cadence Survey II: 49 Variables but No Planetary Transits of a White Dwarf

## TL;DR

This survey used minute cadence photometry over eight nights to search for planetary transits around white dwarfs but found none, while discovering 49 variable stars, including new systems.

## Contribution

The study provides the first extensive high-cadence photometric survey targeting white dwarfs for planetary transits and reports new variable star discoveries.

## Key findings

- No planetary transits detected around ~370 white dwarfs.
- Identified 49 variable stars, including 23 binaries and pulsators.
- Ruled out short-duration transits in the observed field.

## Abstract

We present minute cadence photometry of 31732 point sources observed in one 3 $deg^{2}$ DECam pointing centred at RA = 09:03:02 and Dec = -04:35:00 over eight consecutive half-nights. We use these data to search for eclipse-like events consistent with a planetary transit of a white dwarf and other sources of stellar variability within the field. We do not find any significant evidence for minute-long transits around our targets, hence we rule out planetary transits around ~370 white dwarfs that should be present in this field. Additionally, we identify 49 variables, including 40 new systems. These include 23 detached or contact stellar binaries, 1 eclipsing white dwarf + M dwarf binary, 16 $\delta$ Scuti, three RR Lyrae, and two ZZ Ceti pulsators. Results from the remaining two fields in our survey will allow us to place more stringent constraints on the frequency of planets orbiting white dwarfs in the habitable zone.