iSHELL: a 1–5 micron R = 80,000 Immersion Grating Spectrograph for the NASA Infrared Telescope Facility

iSHELL is a 1.06–5.3 μm high spectral resolution spectrograph built for the 3.2 m NASA Infrared Telescope Facility (IRTF) on Maunakea, Hawaii. Dispersion is accomplished with a silicon immersion grating in order to keep the instrument small enough to be mounted at the Cassegrain focus of the telescope. The white pupil spectrograph produces resolving powers of up to about R ≡ λ/δλ = 80,000 (0.″375 slit). Cross-dispersing gratings mounted in a tiltable mechanism allow observers to select different wavelength ranges and, in combination with a slit wheel and Dekker mechanism, slit widths ranging from 0.″375 to 4.″0 and slit lengths ranging from 5″ to 25″. One Teledyne 2048 × 2048 HAWAII-2RG array is used in the spectrograph, and one Raytheon 512 × 512 Aladdin 2 array is used in a 1–5 μm slit viewer for object acquisition, guiding, and scientific imaging. iSHELL has been in productive regular use on IRTF since first light in 2016 September. In this paper we discuss details of the science case, design, construction and astronomical use of iSHELL.

SHAPU: Forty years on Mystery Persists

In 1975, our team encountered several cases of severe inflammatory eye disease presenting as a white pupil in a red eye with rapid loss of vision. The eyes became soft within a few days with shallow anterior chamber which we called “Malignant Hypotension” in view of the latter’s sinister significance. Unilaterally, little or no pain, predominantly affecting children and difficulty in dilating the pupil and keeping it dilated were some of the other important features. Posterior segment was not visible due to massive exudation in vitreous. Microbiological investigations of aqueous humor did not retrieve any bacterial or fungal organisms. All eyes became pthisical in few weeks despite treatment with topical and subconjunctival antibiotics and steroids. Similar cases appeared again after two years in 1977 with identical presentation and outcome. Both out breaks began during September and lasted until about January- the next year.

Design and Construction of VUES: The Vilnius University Echelle Spectrograph

In February 2014, the Yale Exoplanet Laboratory was commissioned to design, build, and deliver a high resolution ([Formula: see text]) spectrograph for the 1.65[Formula: see text]m telescope at the Molėtai Astronomical Observatory. The observatory is operated by the Institute of Theoretical Physics and Astronomy at Vilnius University. The Vilnius University Echelle Spectrograph (VUES) is a white-pupil design that is fed via an octagonal fiber from the telescope and has an operational bandpass from 400[Formula: see text]nm to 880[Formula: see text]nm. VUES incorporates a novel modular optomechanical design that allows for quick assembly and alignment on commercial optical tables. This approach allowed the spectrograph to be assembled and commissioned at Yale using lab optical tables and then reassembled at the observatory on a different optical table with excellent repeatability. The assembly and alignment process for the spectrograph was reduced to a few days, allowing the spectrograph to be completely disassembled for shipment to Lithuania, and then installed at the observatory during a 10-day period in June of 2015.

Female Bicyclus anynana butterflies choose males on the basis of their dorsal UV-reflective eyespot pupils

Sexual and natural selection pressures are thought to shape the characteristic wing patterns of butterfly species. Here we test whether sexual selection by female choice plays a role in the maintenance of the male wing pattern in the butterfly Bicyclus anynana . We perform one of the most extensive series of wing pattern manipulations in butterflies, dissecting every component of the ‘bulls-eye’ eyespot patterns in both ventral and dorsal wing surfaces of males to test the trait's appeal to females. We conclude that females select males on the basis of the size and brightness of the dorsal eyespot's ultraviolet reflecting pupils. Pupil absence is strongly selected against, as are artificially enlarged pupils. Small to intermediate (normal sized) pupils seem to function equally well. This work contradicts earlier experiments that suggest that the size of dorsal eyespots plays a role in female choice and explains why male dorsal eyespots are very variable in size and often have indistinct rings of coloration, as the only feature under selection by females seems to be the central white pupil. We propose that sexual selection by female choice, rather than predator avoidance, may have been an important selective factor in the early stages of eyespot evolution in ancestral Lepidopteran lineages.