High-contrast and resolution near-infrared photometry of the core of R136

Khorrami, Zeinab; Langlois, M.; Clark, Paul; Vakili, F.; Buckner, Anne S. M.; González, Marta; Crowther, P. A.; Wünsch, Richard; Palouš, J.; Lumsden, S. L.; Moraux, E.

doi:10.1093/mnras/stab388

Cited by 11 publications

(21 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Magnitudes and PMs of the HOMAs and the five brightest sources in the core of R136. H95 and K21 are the identification of these sources from Hunter et al (1995) and Khorrami et al (2021), respectively. K 2018 , K 2015 , H, and J are the magnitudes in the SPHERE/IRDIS filters (Khorrami et al 2017(Khorrami et al , 2021.…”

Section: Discussionmentioning

confidence: 99%

“…Photometry is carried out on the two images (left and right) from each epoch, using the same method and criteria as explained in Sect. 3 of Khorrami et al (2021). We needed to repeat the photometric analysis in both epochs for three reasons: 1) the input PSF should be the same in two epochs in order to have a robust photometric analysis; 2) some of the input PSF used in the photometric analysis in the first epoch (Khorrami et al 2017) appeared as multiple systems in 2018 where we use longer exposures; and 3) the photometric analysis of the 2015 data was done on the combined left and right images, but separate photometric analyses of the left and right images were required for the present purpose.…”

Section: Photometrymentioning

confidence: 99%

“…Most of the information on R136 comes from Hubble Space Telescope (HST) observations, which was used to study various parameters including the cluster's star formation history, stellar content, and kinematics (Hunter et al 1995;Andersen et al 2009;De Marchi et al 2011;Cignoni et al 2015). Using the Spectro-Polarimetric Highcontrast Exoplanet Research (SPHERE, Beuzit et al 2019) of the Very Large Telescope (VLT) in 2015 we obtained the first epoch observations of the R136 core (Khorrami et al 2017) in the nearinfrared (NIR), and in 2018 we obtained a second set of observations for this region (Khorrami et al 2021). Comparing the two sets of observations, we monitored the dynamics of the detected Catalogue of reliable-consistent sources is only available in electronic form at the CDS via http://cdsweb.u-strasbg.fr/ cgi-bin/qcat?J/A+A/ Based on observations made with ESO Telescopes at the La Silla Paranal Observatory under programme ID 0102.D0271 and 095.D-0309 sources in the core of R136 searching for High prOper Motion cAndidates (HOMAs 1 ).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Extreme adaptive optics astrometry of R136. Searching for high proper motion stars

Khorrami,

Langlois,

Vakili

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

We compared high-contrast near-infrared images of the core of R136 taken by VLT/SPHERE, in two epochs separated by 3.06 years. For the first time we monitored the dynamics of the detected sources in the core of R136 from a ground-based telescope with adaptive optics. The aim of these observations was to search for High prOper Motion cAndidates (HOMAs) in the central region of R136 (r < 6") where it has been challenging for other instruments. Two bright sources (K< 15 mag and V< 16 mag) are located near R136a1 and R136c (massive WR stars) and have been identified as potential HOMAs. These sources have significantly shifted in the images with respect to the mean shift of all reliable detected sources and their neighbours, and six times their own astrometric errors. We calculate their proper motions to be 1.36 ± 0.22 mas/yr (321 ± 52 km/s) and 1.15 ± 0.11 mas/yr (273 ± 26 km/s). We discuss different possible scenarios to explain the magnitude of such extreme proper motions, and argue for the necessity to conduct future observations to conclude on the nature of HOMAs in the core of R136.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Photometrymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Extreme adaptive optics astrometry of R136. Searching for high proper motion stars

Khorrami,

Langlois,

Vakili

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

show abstract

“…In the future, we envision to use the multi-epoch SPHERE data set obtained on NGC3603 to derive the internal proper motions within this cluster (using the first SPHERE epoch obtained as a reference) and include this information in the catalog. 49 Other calibration fields that were occasionally observed include the θ 1 Ori Trapezium B1-B4 50 and NGC6380 (reference catalog obtained through priv. comm.…”

Section: Astrometric Fields Usedmentioning

confidence: 99%

Lessons learned from SPHERE for the astrometric strategy of the next generation of exoplanet imaging instruments

Maire

Langlois

Delorme

et al. 2021

J. Astron. Telesc. Instrum. Syst.

Self Cite

View full text Add to dashboard Cite

Measuring the orbits of directly imaged exoplanets requires precise astrometry at the milliarcsec level over long periods of time due to their wide separation to the stars (≳10 au) and long orbital period (≳20 yr). To reach this challenging goal, a specific strategy was implemented for the instrument Spectro-Polarimetric High-contrast Exoplanet Research (SPHERE), the first dedicated exoplanet imaging instrument at the Very Large Telescope of the European Southern Observatory (ESO). A key part of this strategy relies on the astrometric stability of the instrument over time. We monitored for five years the evolution of the optical distortion, pixel scale, and orientation to the True North of SPHERE images using the near-infrared instrument IRDIS. We show that the instrument calibration achieves a positional stability of ∼1 mas over 2″ field of views. We also discuss the SPHERE astrometric strategy, issues encountered in the course of the on-sky operations, and lessons learned for the next generation of exoplanet imaging instruments on the Extremely Large Telescope being built by ESO. © The Authors. Published by SPIE under a Creative Commons Attribution 4.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

show abstract

“…In the future, we envision to use the multi-epoch SPHERE data set obtained on NGC3603 to derive the internal proper motions within this cluster (using the first SPHERE epoch obtained as a reference) and include this information in the catalog. 49 Other calibration fields which were occasionally observed include the θ 1 Ori Trapezium B1-B4 50 and NGC6380 (reference catalog obtained through priv. comm.…”

Section: Astrometric Fields Usedmentioning

confidence: 99%

Lessons learned from SPHERE for the astrometric strategy of the next generation of exoplanet imaging instruments

Maire¹,

Langlois²,

Delorme³

et al. 2021

Preprint

View full text Add to dashboard Cite

Measuring the orbits of directly-imaged exoplanets requires precise astrometry at the milliarcsec level over long periods of time due to their wide separation to the stars ( 10 au) and long orbital period ( 20 yr). To reach this challenging goal, a specific strategy was implemented for the instrument Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE), the first dedicated exoplanet imaging instrument at the Very Large Telescope of the European Southern Observatory (ESO). A key part of this strategy relies on the astrometric stability of the instrument over time. We monitored for five years the evolution of the optical distortion, pixel scale, and orientation to the True North of SPHERE images using the near-infrared instrument IRDIS. We show that the instrument calibration achieves a positional stability of ∼1 mas over 2 field of views. We also discuss the SPHERE astrometric strategy, issues encountered in the course of the on-sky operations, and lessons learned for the next generation of exoplanet imaging instruments on the Extremely Large Telescope being built by ESO.

show abstract

High-contrast and resolution near-infrared photometry of the core of R136

Cited by 11 publications

References 39 publications

Extreme adaptive optics astrometry of R136. Searching for high proper motion stars

Extreme adaptive optics astrometry of R136. Searching for high proper motion stars

Lessons learned from SPHERE for the astrometric strategy of the next generation of exoplanet imaging instruments

Lessons learned from SPHERE for the astrometric strategy of the next generation of exoplanet imaging instruments

Contact Info

Product

Resources

About