Related papers: Post-AGB Stars as Standard Extragalactic Candles
I report the discovery that the 9th-magnitude Galactic-halo star BD+14$^\circ$3061 is a member of the rare class of luminous metal-poor "yellow post-AGB" stars. Its Gaia DR2 parallax implies an absolute magnitude of $M_V=-3.44\pm0.27$, and…
The evolutionary status of 24 post-AGB stars is presented based on Gaia DR3 data. All 24 stars have parallaxes accurate to better than 3 X sigma and have RUWE values less than 1.4. Based on the Gaia DR3 distances the absolute luminosities…
We have used the WFPC2 camera of the Hubble Space Telescope to obtain deep F814W images of a blank field in the Virgo Cluster located 41 arcmin northwest of M87. We perform star counts in that field, and in another Virgo field observed by…
We present HR Diagrams for the massive star populations in M31 and M33 including several different types of emission-line stars: the confirmed Luminous Blue Variables (LBVs), candidate LBVs, B[e] supergiants and the warm hypergiants. We…
Post-AGB stars are key objects for the study of the dramatic morphological changes of low- to intermediate-mass stars on their evolution from the Asymptotic Giant Branch (AGB) towards the Planetary Nebula stage. There is growing evidences…
We report the discovery of three large (R29 >~ 1 arcminute) extremely low surface brightness (mu_(V,0) ~ 27.0) galaxies identified using our deep, wide-field imaging of the Virgo Cluster from the Burrell Schmidt telescope. Complementary…
We have used deep I-band (F814W) images from the HST archive to study the globular cluster systems around the brightest cluster galaxies (BCGs) in Abell 262, 3560, 3565 and 3742. Three of these BCGs have inner dust lanes and peculiar…
The M33 galaxy is a nearby, relatively metal-poor, late-type spiral. Its proximity and almost face-on inclination means that it projects over a large area on the sky, making it an ideal candidate for wide-field CCD mosaic imaging.…
Post-AGB stars are the final stage of evolution of low-intermediate mass stars (M<8 Solar Masses). Those in binary systems have stable circumbinary discs. Using data from Herschel (PACS/SPIRE), we extend the SEDs of 50 galactic post-AGB…
Asymptotic Giant Branch (AGB) stars are good tracers of the Galactic structure. They are bright in the infrared and can therefore be detected even in the most obscured regions of the Galaxy. Maser emission from their circumstellar envelopes…
The three major large-scale, diffuse $\gamma$-ray structures of the Milky Way are the Galactic disk, a bulge-like GeV excess towards the Galactic center, and the Fermi bubble. Whether such structures can also be present in other normal…
Slit spectra, covering the rest frame near-ultraviolet and blue wavelength regions, are combined with moderately deep g and R images to investigate radial population gradients in the brightest components of six z=0.2 galaxy clusters…
Obscured by their circumstellar dusty envelopes post-AGB stars emit a large fraction of their energy in the infrared and thus, infrared sky surveys like IRAS were essential for discoveries of post-AGBs in the past. Now, with the AKARI…
We present ultraviolet photometry for globular clusters (GCs) in M31 from 15 square deg of imaging using the Galaxy Evolution Explorer (GALEX). We detect 200 and 94 GCs with certainty in the near-ultraviolet (NUV; 1750 - 2750 Angstroms) and…
Binary post-asymptotic giant branch (post-AGB) stars are thought to be the products of a strong but poorly-understood interaction during the AGB phase. The aim of this contribution is to update the orbital elements of a sample of galactic…
We have obtained medium-resolution spectra of seven UV-bright stars discovered on images of four southern globular clusters obtained with the Ultraviolet Imaging Telescope (UIT). Effective temperatures, surface gravities and helium…
The Advanced Camera for Surveys (ACS) on HST has been used to image two fields in the core of the Virgo cluster that contain a number of dwarf elliptical galaxies. The combined F555W and F814W images have resolved red giant stars in these…
We have discovered the stellar counterpart to the ALFALFA Virgo 7 cloud complex, which has been thought to be optically dark and nearly star-free since its discovery in 2007. This ~190 kpc long chain of enormous atomic gas clouds…
We present photometry for all bright red giant branch (RGB), horizontal branch (HB), and asymptotic giant branch (AGB) stars within 10' of the center of M13. We find support for the idea that the population of HB stars redder than the…
Stellar photospheres of post-asymptotic giant branch stars bear witness to the internal chemical enrichment processes, integrated over their entire stellar evolution. Here we study post-AGB stars in the Large Magellanic Cloud (LMC). With…