activity
19972018
most citedDiscovery of an HI Counterpart to the Extended Tail of Mira

47 citations · 252 across the 15 of their papers we have counts for

collaborators

16 papers

astro-ph.SR2018

The loss of large amplitude pulsations at the end of AGB evolution

Dieter Engels, Sandra Etoka, Eric Gerard

Since 2013 we are performing with the Nancay Radio Telescope (NRT) a monitoring program of >100 Galactic disk OH/IR stars, having bright 1612-MHz OH maser emission. The variations…

astro-ph.SR2017★ 4 cited

Distances of Stars by mean of the Phase-lag Method

Sandra Etoka, Dieter Engels, Eric Gerard +1

Variable OH/IR stars are Asymptotic Giant Branch (AGB) stars with an optically thick circumstellar envelope that emit strong OH 1612 MHz emission. They are commonly observed throug…

astro-ph.SR2017★ 3 cited

HI emission from the red giant Y CVn with the VLA and FAST

D. T. Hoai, P. T. Nhung, L. D. Matthews +2

Imaging studies with the VLA have revealed HI emission associated with the extended circumstellar shells of red giants. We analyse the spectral map obtained on Y CVn, a J-type carb…

astro-ph.SR2015★ 1 cited

Phase-lag Distances of OH Masing AGB Stars

D. Engels, S. Etoka, E. Gerard +1

Distances to AGB stars with optically thick circumstellar shells cannot be determined using optical parallaxes. However, for stars with OH 1612 MHz maser emission emanating from th…

astro-ph.SR2015★ 18 cited

Discovery of a Shell of Neutral Atomic Hydrogen Surrounding the Carbon Star IRC+10216

L. D. Matthews, E. Gerard, T. Le Bertre

We have used the Robert C. Byrd Green Bank Telescope to perform the most sensitive search to date for neutral atomic hydrogen (HI) in the circumstellar envelope (CSE) of the carbon…

astro-ph.GA2013★ 2 cited

Long-term polarimetric observations of OH127.8+0.0

P. Wolak, M. Szymczak, E. Gerard

OH 1612 and 1667 MHz masers from the well known object OH127.8+0.0 were mon- itored in full-polarization mode over a period of 6.5 years and mapped with MERLIN at one epoch. The OH…