Search Publications
Extremely Red Objects in the Field of QSO 1213-0017: A Galaxy Concentration at Z=1.31
Dickinson, Mark E.; Steidel, Charles C.; Graham, James R. +4 more
We have discovered a concentration of extremely red objects (EROs; R-K>6) in the field of the z=2.69 quasar QSO 1213-0017 (UM 485), which is a significant overabundance compared with the field ERO surface density. The optical/near-IR colors of the EROs and numerous other red galaxies in this field are consistent with elliptical galaxies at z=1-…
Rapid photometry of supernova 1987A: a 2.14 ms pulsar?
Kristian, Jerome A.; Danks, Anthony C.; Kunkel, William E. +9 more
We have monitored Supernova 1987A in optical/near-infrared bands using various high-speed photometers from a few weeks following its birth until early 1996 in order to search for a pulsar remnant. While we have found no clear evidence of any pulsar of constant intensity and stable timing, we have found emission with a complex period modulation nea…
The dynamical evolution of the fragmented, bipolar dust shell around the carbon star IRC +10 216 . Rapid changes of a PPN-like structure?
Weigelt, G.; Men'shchikov, A. B.; Blöcker, T. +2 more
We present high-resolution J-, H-, and K-band observations and the first H-K color image of the carbon star
Stellar Populations in the Phoenix Dwarf (DIRR/DSPH) Galaxy as Observed by Hubble Space Telescope WFPC2
Grillmair, Carl; Smith, Graeme H.; Holtzman, Jon A.
We present Hubble Space Telescope Wide Field Planetary Camera 2 photometry of the central regions of the Phoenix dwarf galaxy. Accurate photometry allows us to (1) confirm the existence of the horizontal branch previously detected by ground-based observations and use it to determine a distance to Phoenix, (2) clearly detect the existence of multip…
Circumnuclear structure and kinematics in the active galaxy NGC 6951
Durret, F.; González Delgado, R. M.; Moles, M. +5 more
A study is presented of the central structure and kinematics of the galaxy NGC 6951, by means of broad band B{\arcminIJK} images and high resolution high dispersion longslit spectroscopy, together with archival HST WFPC2 V and NICMOS2 J and H images. We find that there is little ongoing star formation inside the bar dominated region of the galaxy,…
Observations of sunspot transition region oscillations
Wilhelm, K.; Kjeldseth-Moe, O.; Brynildsen, N. +2 more
Oscillations with a period of 3 minutes are observed in the transition region of six sunspots with the Solar and Heliospheric Observatory - SOHO joint observing programme for velocity fields in sunspot regions. Observations of the transition region lines O v λ629 and N v λλ1238, 1242 with the SUMER instrument show significant differences in the am…
Analysis of the Hipparcos Measurements of HD 10697: A Mass Determination of a Brown Dwarf Secondary
Mazeh, Tsevi; Zucker, Shay
HD 10697 is a nearby main-sequence star around which a planet candidate has recently been discovered by means of radial velocity measurements (Vogt et al.). The stellar orbit has a period of about 3 yr, the secondary minimum mass is 6.35 Jupiter masses (MJ), and the minimum semimajor axis is 0.36 mas. Using the Hipparcos data of HD 1069…
The Pleiades, Map-based Trigonometric Parallaxes of Open Clusters. V.
Han, Inwoo; Gatewood, George; de Jonge, Joost Kiewiet
The Multichannel Astrometric Photometer and Thaw Refractor (Thaw/MAP) of the University of Pittsburgh's Allegheny Observatory have been used to determine the trigonometric parallax of the Pleiades star cluster. The parallax determined, 0.00764" with a standard error of +/-0.00043" (corresponding to a distance modulus of 5.59+/-0.12 mag) places the…
Sensitivity of the GOLF signal to combined solar velocity and intensity variations
García, R. A.; Turck-Chièze, S.; Dzitko, H. +6 more
The GOLF instrument provides a stable and continuous measurement of the intensity of spatially integrated sunlight in one wing of the sodium D lines. Because the detected radiation results from atomic scattering, the GOLF signal can be traced to an atomic reference wavelength. The planned operations were to involve a form of relative photometry th…
Discovery of Parsec-sized Dust Shells around AFGL 2688 and AFGL 618
Meixner, M.; Knapp, G. R.; Speck, A. K.
We present ISOPHOT linear scans of two carbon-rich proto-planetary nebulae, AFGL 2688 and AFGL 618. The 53'×3' scans were made with the ISO AOT PHT32 using the 120 and 180 µm filters. Both these objects appear to have very bright central point sources together with extremely extended (radius ~350"-400") dust shells with…