Gaia14aae (ASASSN-14cn) was detected by Gaia on 2014-08-11, during an outburst. Low to intermediate resolution spectra taken at the 4.2m William Herschel Telescope on La Palma, over the nights of 13-15 October 2014, using ISIS+R300B/R158R and ACAM+V400, show double-peaked He emission lines at z=0, with no H.
Such spectra allowed classification of
…→ Read More: Gaia alerts validation with the Loiano telescope confirms Gaia14aae to be the third known eclipsing AM CVn (a candidate SN Ia progenitor).
LEFT: the stars observed in NGC6791 (red/blue: members; magenta/green: non members); CENTER: The uniform Na distribution; RIGHT: The Na-O "anticorrelation" (grey: GCs)
Galactic open and globular clusters (OCs, GCs) appear to inhabit separate regions of the age-mass plane. However, the transition between them is not easily defined because there is some overlap between
…→ Read More: NGC 6791, a normal open cluster after all?
In the currently accepted paradigm for galaxy formation, present-day dwarf galaxies are the leftover of a larger population of small galaxies that was cannibalised during the hierarchical build-up of larger systems like the Milky Way.
Today we observe that dwarf satellites in the surroundings of large galaxies tipically have elliptical shape, are devoid of gas
…→ Read More: Signs of ancient interactions in isolated dwarf galaxies