High Contrast Studies of Nearby Stars with Project 1640


Neil Zimmerman (1,2), Ben R. Oppenheimer (2,1), Sasha Hinkley (3), Douglas Brenner (2), Ian Parry (4), Anand Sivaramakrishnan (2)


(1) Columbia University; (2) American Museum of Natural History; (3) California Institute of Technology; (4) Cambridge Institute of Astronomy


I will review some of the initial science results from Project 1640, a coronagraphic integral field spectrograph at Palomar Observatory. One of these, emerging from our survey of nearby A stars, is the discovery of an M-dwarf companion to Alcor. To reach this point, we first needed to solve some data reduction problems particular to this kind of instrument, including the automatic translation of 4*10^4 closely-packed, coarsely-sampled focal plane spectra to data cubes. We confirmed the physical association between Alcor and the fainter neighboring star (at 1" separation and a contrast of 6 magnitudes) using a novel method of high precision relative astrometry applied to two data sets acquired just 100 days apart, demonstrating common parallactic and proper motion. The same data provided a low-resolution near-infrared spectrum spanning the J and H bands, enabling us to classify the companion as an M3-M4 dwarf. In a separate experiment, we have used Project 1640 as an imaging spectrograph without a coronagraph to achieve spectrally-resolved sub-aperture interferometry with a non-redundant mask.

Attached documents

Lyot2010proc s2 talk ZimmermanN.pdf
PDF, 14.3 Mb