164 citations · 810 across the 72 of their papers we have counts for
26 papers · 1 filter
Detection and Characterization of Microlensing Events due to Isolated Black Holes towards the Magellanic Clouds in the Rubin Observations
Sedighe Sajadian, Martin Makler
Gravitational microlensing surveys potentially discover isolated black holes (IBHs) at large distances through their gravitational effects on apparent brightness and motion of coll…
Self-Lensing Signals in Binary Systems Containing White Dwarfs with Neutron star or Stellar-mass Black hole Companions
Sedighe Sajadian, Man Ho Chan
Light curves from binary systems containing white dwarfs with neutron star or stellar-mass black hole companions (WD+NS and WD+BH) with edge-on orbital planes potentially show self…
Probing periodic trends in the TESS light curves of the seventeen known Double White Dwarf systems
Sedighe Sajadian, Aref Asadi
There is a relatively large population of known double white dwarfs (DWDs) that were mostly discovered through spectroscopic observations and by measuring their radial velocity var…
Study Self-lensing/Eclipsing Signals in Edge-on Double White-Dwarf Systems
Sedighe Sajadian
Stellar lightcurves from edge-on double white dwarf systems(DWDs) have periodic lensing/eclipsing signals at times of alignment between two components as seen by the observer. Here…
Finite-Lens Effect on Self-Lensing in detached White Dwarfs-Main Sequence Binary Systems
Sedighe Sajadian, Hossein Fatheddin
In an edge-on and detached binary system, including a white dwarf (WD) and a main-sequence star (WDMS), when the source star is passing behind the compact companion its light is be…
Simulating Self-Lensing and Eclipsing Signals due to Detached Compact Objects in the TESS Light Curves
Sedighe Sajadian, Niayesh Afshordi
A fraction of Galactic stars have compact companions which could be white dwarfs (WDs), neutron stars (NSs) or stellar-mass black holes (SBHs). In a detached and edge-on binary sys…
Digging deeper into the dense Galactic globular cluster Terzan 5 with Electron-Multiplying CCDs. Variable star detection and new discoveries
R. Figuera Jaimes, M. Catelan, K. Horne +20
Context. High frame-rate imaging was employed to mitigate the effects of atmospheric turbulence (seeing) in observations of globular cluster Terzan 5. Aims. High-precision time-ser…
Gaia21blx: Complete resolution of a binary microlensing event in the Galactic disk
P. Rota, V. Bozza, M. Hundertmark +22
Context. Gravitational microlensing is a method that is used to discover planet-hosting systems at distances of several kiloparsec in the Galactic disk and bulge. We present the an…
Precision measurement of a brown dwarf mass in a binary system in the microlensing event OGLE-2019-BLG-0033/MOA-2019-BLG-035
A. Herald, A. Udalski, V. Bozza +89
Context. Brown dwarfs are poorly understood transition objects between stars and planets, with several competing mechanisms having been proposed for their formation. Mass measureme…
An Isolated Stellar-Mass Black Hole Detected Through Astrometric Microlensing
Kailash C. Sahu, Jay Anderson, Stefano Casertano +90
We report the first unambiguous detection and mass measurement of an isolated stellar-mass black hole (BH). We used the Hubble Space Telescope (HST) to carry out precise astrometry…
Identifying low-amplitude pulsating stars through microlensing observations
Sedighe Sajadian, Richard Ignace, Hilding Neilson
One possibility for detecting low-amplitude pulsational variations is through gravitational microlensing. During a microlensing event, the temporary brightness increase leads to im…
Mass-velocity dispersion relation by using the \textit{Gaia} data and its effect on interpreting short-duration and degenerate microlensing events
Sedighe Sajadian, Sohrab Rahvar, Fatemeh Kazemian
Gravitational microlensing, the lensing of stars in the Milky Way galaxy with other stars, has been used for exploring compact dark matter objects, exoplanets, and black holes. The…
Measuring the stellar atmosphere parameters using follow-up polarimetry microlensing observations
Elahe Khalouei, Sedighe Sajadian, Sohrab Rahvar
We present an analysis of the potential follow-up polarimetry microlensing observation to study the stellar atmospheres of the distant stars. First, we produce synthetic microlensi…
Non-radially pulsating stars as microlensing sources
Sedighe Sajadian, Richard Ignace
We study the microlensing of Non-Radially Pulsating (NRP) stars. Pulsations are formulated for stellar radius and temperature using spherical harmonic functions with different valu…
Detecting the inner regions of discs around sources of microlensing with Roman Space Telescope
Sedighe Sajadian, Ali Salehi
The inner region of circumstellar discs makes an extra near-infrared emission (NIR bump). Detecting and studying these NIR bumps from nearby stars have been done mostly through inf…
Large-scale changes of the cloud coverage in the Indi Ba,Bb system
J. A. Hitchcock, Ch. Helling, A. Scholz +22
We present the results of 14 nights of \textit{I}-band photometric monitoring of the nearby brown dwarf binary, Indi Ba,Bb. Observations were acquired over 2 months, and total…
Microlensing of radially pulsating stars
Sedighe Sajadian, Richard Ignace
Here, we study the microlensing of radially pulsating stars. Discerning and characterizing the properties of distant, faint pulsating stars is achievable through high-cadence micro…
Spitzer Microlensing parallax reveals two isolated stars in the Galactic bulge
Weicheng Zang, Yossi Shvartzvald, Tianshu Wang +90
We report the mass and distance measurements of two single-lens events from the 2017 Spitzer microlensing campaign. The ground-based observations yield the detection of finite-sour…
OGLE-2017-BLG-1186: first application of asteroseismology and Gaussian processes to microlensing
Shun-Sheng Li, Weicheng Zang, Andrzej Udalski +102
We present the analysis of the event OGLE-2017-BLG-1186 from the 2017 Spitzer microlensing campaign. This is a remarkable microlensing event because its source is photometrically b…
Microlensing Parallax for OGLE-2017-BLG-0896 Reveals a Counter-Rotating Low-Mass Brown Dwarf
Yossi Shvartzvald, Jennifer C. Yee, Jan Skowron +63
The kinematics of isolated brown dwarfs in the Galaxy, beyond the solar neighborhood, is virtually unknown. Microlensing has the potential to probe this hidden population, as it ca…
OGLE-2017-BLG-0329L: A Microlensing Binary Characterized with Dramatically Enhanced Precision Using Data from Space-based Observations
C. Han, S. Calchi Novati, A. Udalski +54
Mass measurements of gravitational microlenses require one to determine the microlens parallax $\pie$, but precise $\pie$ measurement, in many cases, is hampered due to the subtlet…
Stellar rotation effects in polarimetric microlensing
Sedighe Sajadian
It is well known that the polarization signal in microlensing events of hot stars is larger than that of main-sequence stars. Most hot stars rapidly rotate around their stellar axe…
Polarimetric microlensing of circumstellar disks
Sedighe Sajadian, Sohrab Rahvar
We study the benefits of polarimetry observations of microlensing events to detect and characterize circumstellar disks around the microlensed stars located at the Galactic bulge.…
Detecting stellar spots through polarimetry observations of microlensing events in caustic-crossing
Sedighe Sajadian
In this work, we investigate if gravitational microlensing can magnify the polarization signal of a stellar spot and make it be observable. A stellar spot on a source star of micro…