Interferometric Observations of V1663 Aquilae (Nova Aql 2005)

TL;DR

This study used near-infrared interferometry to directly observe the shape, size, and expansion of nova V1663 Aql, providing a new distance estimate and insights into its asymmetric fireball evolution.

Contribution

First direct interferometric measurement of V1663 Aql's shape, size, and expansion, leading to an independent distance estimate and evidence of asymmetry.

Findings

Measured asymmetric fireball shape.

Determined expansion rate of 0.21 mas/day.

Estimated distance of 8.9 kpc.

Abstract

We have resolved the classical nova V1663 Aql using long-baseline near-IR interferometry covering the period from 5--18 days after peak brightness. We directly measure the shape and size of the fireball, which we find to be asymmetric. In addition we measure an apparent expansion rate of 0.21 +/- 0.03 mas/day. Assuming a linear expansion model we infer a time of initial outburst approximately 4 days prior to peak brightness. When combined with published spectroscopic expansion velocities our angular expansion rate implies a distance of 8.9 +/- 3.6 kpc. This distance measurement is independent of, but consistent with, determinations made using widely available photometric relations for novae.