The ultracool helium-atmosphere white dwarf companion of PSR J0740+6620?

Beronya, D. M.; Karpova, A. V.; Kirichenko, A. Yu; Zharikov, S. V.; Zyuzin, D. A.; Shibanov, Yu A.; Cabrera-Lavers, A.
Bibliographical reference

Monthly Notices of the Royal Astronomical Society, Volume 485, Issue 3, p.3715-3720

Advertised on:
Number of authors
IAC number of authors
Refereed citations
We report detection of the likely companion of the binary millisecond pulsar (MSP) J0740+6620 with the Gran Telescopio Canarias in the r' and i' bands. The position of the detected starlike source coincides with the pulsar coordinates within the 1σ uncertainty of ≈0.2 arcsec. Its magnitudes are r' = 26.51 ± 0.17 and i' = 25.49 ± 0.15. Comparing the data with the white dwarf (WD) cooling tracks suggests that it can be an ultracool helium-atmosphere WD with the temperature ≲3500 K and cooling age ≳5 Gyr. The age is consistent with the pulsar characteristic age corrected for kinematic effects. This is the reddest source among known WD companions of MSPs. Detection of the source in other bands would be useful to clarify its properties and nature.
Related projects
Project Image
Morphology and dynamics of the Milky Way

This project consists of two parts, each differentiated but both complementary: morphology and dynamics. Detailed study of the morphology of the Milky Way pretends to provide a data base for the stellar distribution in the most remote and heavily obscured regions of our Galaxy, through the development of semiempirical models based on the

López Corredoira