The Haystack Telescope is an antenna with a diameter of 37~m and an elevation-dependent surface accuracy of ≤100μm that is capable of millimeter-wave observations. The radome-enclosed instrument serves as a radar sensor for space situational awareness, with about one-third of the time available for research by MIT Haystack Observatory. Ongoing testing with the K-band (18-26~GHz) and W-band receivers (currently 85-93~GHz) is preparing the inclusion of the telescope into the Event Horizon Telescope (EHT) array and the use as a single-dish research telescope. Given its geographic location, the addition of the Haystack Telescope to current and future versions of the EHT array would substantially improve the image quality.
@article{arxiv.2301.02713,
title = {The Haystack Telescope as an Astronomical Instrument},
author = {Jens Kauffmann and Ganesh Rajagopalan and Kazunori Akiyama and Vincent Fish and Colin Lonsdale and Lynn D. Matthews and Thushara G. S. Pillai},
journal= {arXiv preprint arXiv:2301.02713},
year = {2023}
}