Extended Table
PREFACE: Scope and purpose of this essay This online essay is an extended version of the essay in the printed-edition Handbook, containing all the material of its printed-edition accompaniment, but adding material of its own. The accompanying online table is likewise an extended version of the printed-edition table, (a) with extra stars (after providing for multiplicity, as we explain below, the brightest MK-classified 322, allowing for variability, where the printed edition has almost 30 fewer, allowing for variability: our cutoff is mag. ~3.55), and (b) with additional remarks for most of the duplicated stars. We use a dagger superscript (†) to mark data cells for which the online table supplies some additional information, some context, or a caveat. The online essay and table try to address the needs of three kinds of serious amateur: amateurs who are also astrophysics students (whether or not enrolled formally at some campus); amateurs who, like many in RASC, assist in public outreach, through some form of lecturing; and amateurs who are planning their own private citizen-science observing runs, in the spirit of such “pro-am” organizations as AAVSO. Additionally, we would hope that the online project will help serve a constituency of sky-lovers, whether professional or amateur, who work with the heavens in an unambitious and contemplative spirit, seeking to understand at the eyepiece, or even with the naked eye, the realities behind the little that their limited circumstances may allow them to see. (This is the same contemplative exercise as is proposed for the Cyg X-1 black hole, with its gas-dumping supergiant companion HD226868, in the Handbook printed-editions “Expired Stars” essay: with a small telescope, or even with binoculars, we first find HD226868, and then take a moment to ponder in awe the accompanying unobserved realities of gas-fed hot accretion disk, event horizon, and spacetime singularity.) Our online project, started as a supplement to the 2017 Handbook, must be considered still in its rather early stages.
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