Search

One of the long-term goals of exoplanet science is the atmospheric characterization of dozens of small exoplanets in order to understand their diversity and search for habitable worlds and potential biosignatures. Achieving this goal requires a space mission of sufficient scale. We seek to quantify the exoplanet detection performance of a space-based mid-infrared nulling interferometer that measures the thermal emission of exoplanets. For this, we have developed an instrument simulator that considers all major astrophysical noise sources and coupled it with Monte Carlo simulations of a synthetic exoplanet population around main-sequence stars within 20 pc. This allows us to quantify the number (and types) of exoplanets that our mission concept could detect over a certain time period. Two different scenarios to distribute the observing time among the stellar targets are discussed and different apertures sizes and wavelength ranges are considered. Within a 2.5-year initial search phase, an interferometer consisting of four 2 m apertures with a total instrument throughput of 5% covering a wavelength range between 4 and 18.5 $\mu$m could detect up to ~550 exoplanets with radii between 0.5 and 6 R$_\oplus$ with an integrated SNR$\ge$7. At least ~160 of the detected exoplanets have radii $\le$1.5 R$_\oplus$. Depending on the observing scenario, ~25-45 rocky exoplanets (objects with radii between 0.5 and 1.5 $_{\oplus}$) orbiting within the empirical habitable zone (eHZ) of their host stars are among the detections. With an aperture size of 3.5 m, the total number of detections can increase to up to ~770, including ~60-80 rocky, eHZ planets. With 1 m aperture size, the maximum detection yield is ~315 exoplanets, including $\le$20 rocky, eHZ planets. In terms of predicted detection yield, such a mission can compete with large single-aperture reflected light missions. (abridged), Comment: Accepted for publication by A&A - some typos corrected and affiliations updated; 14 pages main text (incl. 14 figures); first paper in the LIFE paper series; papers II (arXiv:2203.00471) and III (arXiv:2112.02054) are also available

The only way to detect planets around stars at distances greater than or similar to several kpc is by (photometric or astrometric) microlensing (mu L) observations. In this paper, we show that the capability of photometric mu L extends to the detection of signals caused by planets around stars in nearby galaxies (e.g. M31) and that there is no other method that can achieve this. Due to the large crowding, mu L experiments towards M31 can only observe the high-magnification part of a lensing light curve. Therefore, the dominating channel for mu L signals by planets is in distortions near the peak of high-magnification events as discussed by Griest & Safizadeh (1998). We calculate the probability to detect planetary anomalies for mu L experiments towards M31 and find that jupiter-like planets around stars in M31 can be detected. Though the characterization of the planet(s) involved in this signal will be difficult, the absence of such signals can yield strong constraints on the abundance of jupiter-like planets.

The only way to detect planets around stars at distances greater than or similar to several kpc is by (photometric or astrometric) microlensing (mu L) observations. In this paper, we show that the capability of photometric mu L extends to the detection of signals caused by planets around stars in nearby galaxies (e.g. M31) and that there is no other method that can achieve this. Due to the large crowding, mu L experiments towards M31 can only observe the high-magnification part of a lensing light curve. Therefore, the dominating channel for mu L signals by planets is in distortions near the peak of high-magnification events as discussed by Griest & Safizadeh (1998). We calculate the probability to detect planetary anomalies for mu L experiments towards M31 and find that jupiter-like planets around stars in M31 can be detected. Though the characterization of the planet(s) involved in this signal will be difficult, the absence of such signals can yield strong constraints on the abundance of jupiter-like planets.

The only way to detect planets around stars at distances of several kpc is by (photometric or astrometric) microlensing observations. In this paper, we show that the capability of photometric microlensing extends to the detection of signals caused by planets around stars in nearby galaxies (e.g. M31) and that there is no other method that can achieve this. Due to the large crowding, microlensing experiments towards M31 can only observe the high-magnification part of a lensing light curve. Therefore, the dominating channel for microlensing signals by planets is in distortions near the peak of high-magnification events as discussed by Griest and Safizadeh. We calculate the probability to detect planetary anomalies for microlensing experiments towards M31 and find that jupiter-like planets around stars in M31 can be detected. Though the characterization of the planet(s) involved in this signal will be difficult, the absence of such signals can yield strong constraints on the abundance of jupiter-like planets., Comment: 16 LaTex Pages, including 1 Postscript Figures, submitted to A&A; title changed, one more author added, completely revised version: central point is detecting planet in nearby galaxies and one more technique is taken into consideration