Faint Features of Interacting Galaxies Revealed by the Digital Coaddition of 13 Tech-Pan Films of the Virgo Cluster

We have digitally coadded APM scans of 13 Kodak TechPan films of the SE region of the Virgo Cluster of galaxies. The ≈6.2°×6.2°field of the R-band films combined with the resolution of ≈2 arcsec pixel^- results in data-file sizes of about 222 MBytes. The 13 scanned films have been aligned, coadded, corrected for vignetting effects and cleaned of stellar features. To illustrate the astrophysical uses of this technique, we present high-contrast images of a sample of interacting galaxies in the field. Several very faint features (but very clearly seen in the coadded array) – such as the interaction between IC 3481,IC 3481A and IC 3483, and NGC 4410A and B and IC 790 – have been presented with clarity for the first time. This revised version was published online in July 2006 with corrections to the Cover Date.     

Two jets from the Orion nebula (M42) 'proplyds': kinematics, morphologies and origins

A spatially unresolved velocity feature, with an approaching radial velocity of  ≈100 km s⁻¹  with respect to the systemic radial velocity, in a position–velocity array of [O  iii ] 5007-Å line profiles is identified as the kinematical counterpart of a jet from the proplyd LV 5 (158–323) in the core of the Orion nebula. The only candidate in Hubble Space Telescope ( HST ) imagery for this jet appears to be a displaced, ionized knot. Also an elongated jet projects from the proplyd GMR 15 (161–307). Its receding radial velocity difference appears at  ≈80 km s⁻¹  in the same position–velocity array.
A 'standard' model for jets from young, low-mass stars invokes an accelerating, continuous flow outwards with an opening angle of a few degrees. Here an alternative explanation is suggested which may apply to some, if not all, of the proplyd jets. In this, a 'bullet' of dense material is ejected which ploughs through dense circumstellar ambient gas. The decelerating tail of material ablated from the surface of the bullet would be indistinguishable from a continuously emitted jet in current observations.     

WASP-14b: 7.3 MJ transiting planet in an eccentric orbit

We report the discovery of a 7.3 M _J exoplanet WASP-14b, one of the most massive transiting exoplanets observed to date. The planet orbits the 10th-magnitude F5V star USNO-B1 11118−0262485 with a period of 2.243 752 d and orbital eccentricity   e = 0.09  . A simultaneous fit of the transit light curve and radial velocity measurements yields a planetary mass of 7.3 ± 0.5 M _J and a radius of 1.28 ± 0.08 R _J. This leads to a mean density of about 4.6 g cm⁻³ making it the densest transiting exoplanets yet found at an orbital period less than 3 d. We estimate this system to be at a distance of  160 ± 20  pc. Spectral analysis of the host star reveals a temperature of  6475 ± 100 K, log  g = 4.07  cm s⁻² and   v sin  i = 4.9 ± 1.0  km s⁻¹, and also a high lithium abundance,  log  N (Li) = 2.84 ± 0.05  . The stellar density, effective temperature and rotation rate suggest an age for the system of about 0.5–1.0 Gyr.     

Scanning Fabry-Pérot interferometers for nebular studies

The reasons for applying scanning Fabry-Pérot interferometers to the study of faint but extensive gaseous nebulae are outlined. Three ways of increasing the luminosity-resolutin product of the Fabry-Pérot are then investigated.     

An investigation of a peculiar nebula in monoceros

A faint nebula, between the Rosette and NGC 2264, appears to be a supernova remnant. This was photographed with long exposures through narrow filters centred on the bright nebular emission lines. Interferograms were also taken. These revealed extensive regions emitting broad lines, and showed that the nebula did not have the large expansion velocity that was expected.     

A comparison of the performances of an insect-eye Fabry-Perot spectrograph and a classical Fabry-Perot monochromator

The performance of an image-tube insect-eye Fabry-Perot spectrograph is compared to a classical Fabry-Perot monochromator when used on some topical nebular problems.     

A new large supernova remnant in the southern sky?

A faint filamentary structure on a Southern Schmidt plate is thought to be a supernova remnant.