Aaron E. Watkins et al 2018 ApJL 858 L16
A vast cloud of ionized gas was discovered 32 kpc north of the interacting system M51. The gas may have been expelled from the inner regions of the M51 system and subsequently ionized by shocks or a fading AGN.
Darryl Seligman and Gregory Laughlin 2018 AJ 155 217
Based on expected arrival rates of interstellar asteroids like ‘Oumuamua, and with the detection capabilities of LSST, wait times of ~10 years are likely between opportunities to intercept such asteroids with spacecraft.
Eric J. Hallman et al 2018 ApJ 859 44
Chandra observations of the merging galaxy cluster Abell 115 may reveal interaction of the bow shocks driven into the intracluster medium by the motion of the subclusters relative to one another.
T. E. Strohmayer et al 2018 ApJL 858 L13
Neutron Star Interior Composition Explorer (NICER) observations of the accreting millisecond X-ray pulsar (AXMP) IGR J17062−6143 show it has the shortest known orbital period for an AMXP: 38 minutes.
Meng Gu et al 2018 ApJ 859 37
Optical spectra for three of the ultra-diffuse galaxies in the Coma cluster reveal very old and metal-poor star populations, suggesting stellar mass plays a strong role in setting stellar population properties.
Kathryn F. Neugent et al 2018 AJ 155 207
The first runaway yellow supergiant has been discovered in the Small Magellanic Cloud. Its large radial velocity suggests it originated in a binary system where the primary exploded as a supernova.