The spectrum of the Kitt Peak night sky

Abstract

We have obtained absolute spectrophotometry of the Kitt Peak night sky at a variety of azimuths and zenith angles. Our zenith measurements confirm the finding of Pilachowski et al. that Kitt Peak is still a dark site, as we find (B) = 22.8 mag/arc sec 2 and (V) = 21.9 mag/arc sec 2 on 1988 February 18, a night of fairly low solar activity. (A year later the sky was appreciably brighter; this increase correlates well with solar activity as measured from the 10-cm flux.) The "pseudocontinuum" encountered by spectroscopists is about 0.02-0.05 mag/arc sec 2 darker in B and 0.2-0.3 mag/arc sec 2 darker in V than the broad-band measures. The major line contributor to the B band is Hg, while the dominant source of contamination to the V-band measures are atmospheric lines, most notably O IX5577. Using fluxed observations of street lamps we find that the relative contribution to light pollution in the yellow-red (5000 Á-6500 Á) is 10% Hg, 30% LPS, and 60% HPS. The sky brightness increases a few tenths going from the zenith to a zenith distance of 60°, but the contribution of light pollution remains small. No significant azimuthal effects are seen : The sky is as dark toward Phoenix or Tucson as toward anywhere else, at least for zenith distances of 60° or less.Comparison with earlier measurements of the Kitt Peak sky brightness suggests that there has been no significant increase in light pollution at Kitt Peak from the mid-1960s to the late 1980s, a fact which we attribute to the stringent lighting ordinances adopted by the state.

Analysis of the Schmidt, Cohen & Margon (1980) Features in the Red Rectangle Nebula

“…2), independent of direction (figs. 1a and 1b in [12]) and constant over the years [7,12], except maybe in the 5800Å region ( fig. 2 in [7]).…”

“…Night sky spectra in the visible, at Kitt Peak and Mount Hopkins observatories, are describe in [7,12]. They have an identical shape (figs.…”

Understanding extreme quasar optical variability with CRTS – I. Major AGN flares

“…All nights listed in Table A1 were photometric, and we processed the data using standard techniques within IRAF. For all but the 2015 December observation, we calibrated the data using standard stars from Stone & Baldwin (1983, 1984 and Massey & Gronwall (1990) observed on the same nights using the same instrument configuration; for the 2015 December observation, we used an archival sensitivity function obtained from similar standard stars observed with an identical instrument configuration. For all 13 sources, the spectroscopy revealed quasars with multiple emission features providing robust redshift identifications.…”

Particulate matter as an amplifier for astronomical light pollution

“…Measurements of the light pollution of astronomical observations began in the 1960s and 1970s, mainly in the framework of studies of the spectrum of the night sky (Walker 1973;Turnrose 1974;Osterbrock, Walker & Koski 1976;Massey, Gronwall & Pilachowski 1990;Osterbrock & Martel 1992;Massey & Foltz 2000;Slanger et al 2003). Another group of studies consisted of estimations of the night-sky quality at astronomical centres (Benn & Ellison 1998;Massey & Foltz 2000;Patat 2003).…”