1 November 2023 to 15 May 2024
Asia/Bangkok timezone

Cycle 6 (2018-2019)

ID, Title, PI


C06_001: Time-series spectroscopy of 9 eclipsing binary stars with a pulsating component

(Kyeongsoo Hong, KASI)

We will measure the radial velocities and temperatures for 9 eclipsing binaries (EBs) with a pulsating star to obtain their physical properties. Pulsating EBs that show both eclipses and pulsations are very interesting subjects for investigating the structure and evolution of stars though their binary components, such as δ Sct, γ Dor, red giant, and subdwarf B. The systems can be considered a good astrophysical laboratory for studying mass-transfer processes and binary evolution. We will investigate the evolutionary history of selected EBs by comparing its physical parameters with stellar evolutionary models. For this study, we propose to perform follow-up spectroscopic observations for interesting oscillating EBs with a medium resolution echelle spectrograph (MRES) mounted on the 2.4m Thai National Telescope (TNT) and study the structure and evolution of stars through asteroseismology and binary properties.

C06_002: The Radial Velocity of Exterme Mass Ratio Contact Binary

(Xiao Zhou, NARIT)

Extreme mass ratio contact binary (EMRCB) is at the final evolutionary stage of short-period close binary star and may be the progenitor star of rapidly rotating single star such as blue straggler star, FK Com-type star. Extreme mass ratio contact binary is predicted to merge at last and the stellar merger will ignite optical outburst which are so luminous that can even compare with the explosion of supernova. It is potential candidate of the luminous red novae. More and more extreme mass ratio contact binaries are reported owing to the sky survey projects carried out in recent years, such as the Optical Gravitational Lensing Experiment (OGLE), the Kepler mission and the All Sky Automated Survey (ASAS). However, we usually get the mass ratio of binaries with the q-search method because of the lack of radial velocity curves. In our research project, we would like to obtain the radial velociyy curves of several important contact binaries using the MRES equipped to the TNO 2.4 m telescope. Then, the accurate mass ratio of the binary systems and their stellar atmospheric parameters will be determined.

C06_004: Study of Chemical and Dynamical Evolution of M31 Using Outer Halo Globular Clusters

(Zhou Fan, NAOC)

The mechanisms involved in galaxy formation and evolution remain one of the major unsolved problems in astronomy. Spectral studies of halo globular clusters (GCs) will provide unique information about the accretion history of the host galaxy. We request two nights to observe a sample of GCs in M31’s outer halo with optical spectra using the Middle Resolution fibre-fed Echelle Spectrograph (MRES) mounted on the 2.4-m telescope. For the first time, detailed chemical abundances ([Fe/H] and [α/Fe] ratios) will be calculated from the medium-resolution (R ∼ 15,000) spectra. With a joint spatial-kinematical-metallicity analysis, this program will help us investigate chemically peculiar GCs, the difference between the disk and halo GC system, and the chemodynamical structure of M31 and its assembly history in more detail. Comparing with previous studies of additional spiral galaxies and their GC systems, we may further reveal how pervasive the different modes of GC formation are, and how representative M31 and the MW are of other galaxies.

C06_005: Searching for the First group of red-dwarf contact binaries

(Liying Zhu, Yunnan Obs.)

Contact binaries have the lowest angular momentum and shortest orbital periods among main-sequence binaries. Their formation and evolution are unsolved problems in Astrophysics. At least 80% of all stars in the Galaxy are Red dwarfs (M-type stars). However, to date, only a few red-dwarf contact binary were discovered. Thanks to some surveys in the world (e.g., SDSS and SuperWASP), some short-period (P < 0.22 days) reddwarf binary candidates were discovered. Some of them have been monitored photometrically by us with several small telescopes. Based on those photometric observations, we have selected a group of red-dwarf contact binary candidates. In order to confirm them, the spectroscopic data of these candidates are urgently required by using the MRES attached to 2.4m telescope of Thailand. Our scientific purposes are to search for the first group of red-dwarf contact binaries and investigate their physical properties. These results will shed light on the formation and evolution of contact binary stars, and will help us to understand the magnetic activities of red dwarfs.

C06_006: Searching for extrasolar planets orbiting white-dwarf binaries

(Shengbang Qian, Yunnan Obs.)

One of the most interesting things that we have learnt about extrasolar planets is that they can exist almost anywhere. Investigations have shown that white-dwarf binaries could be planetary hosting stars. In this project, we intend to monitor some white-dwarf eclipsing binary photometrically with the 2.4-m TNT telescope. Based on those observations, mid-eclipse times of the sample stars will be determined. Our scientific purposes are to search for and to investigate circumbinary planets orbiting white-dwarf binary stars by analyzing the light travel-time effect. These results will shed light to the formation and evolution of circumbinary planets, and will help to understand the ultimate fate of planets and the late evolutionary stage of binary stars. Our data can also be used to study magnetic activity of the red-dwarf component stars that can provide some information on CV evolution and outburst.

C06_007: Search for and investigate progenitors of luminous red novae

(Shengbang Qian, Yunnan Obs.)

Luminous red novae (LRNe) are a rare type of stellar outbursts that are typically more luminous than most classical novae. Investigations have shown that they are produced from the merging of evolved deep-contact binary stars. In this project, we will select some evolved binary stars based on the LAMOST data. Then we intend to monitor some of them photometrically with the 2.4-m TNT telescope. Based on those observations, basically physical parameters will be determined by using the W-D method and their geometrical structures and evolutionary states will be understood. Our scientific purposes are to search for extremely deep-contact binaries and then investigate the merging of deep-contact binaries and the origin of luminous red novae outbursts. These results will shed light to the formation and evolution of the progenitors of γ-ray bursts. The investigations will also help to explain several astrophysical phenomena (e.g. the origin of magnetic fields of massive stars and the formations of stellar massive black holes).

C06_008: Space density of Cataclysmic Variables 

(Amornrat Aungwerojwit, Naraesuan U.)

Cataclysmic variables are an excellent benchmark population to test, calibrate, and develop binary population synthesis models. The Sloan Digital Sky Survey (SDSS) produced the deepest and most homogenous CV sample to date, highlighting the importance of the faintest systems to confirm and calibrate models. The spectroscopic completeness of SDSS plummets below i=19.1. However, it is exactly in this range that the composition of the Galactic CV population undergoes a major change. Towards fainter magnitudes the fraction of low-luminosity systems increase and probably dominate the space density of CVs. We propose here to extend the depth of the SDSS CV sample by obtaining TNT observations of faint CV candidates in the SDSS footprint and to measure their orbital periods with the ultimate goal of establishing a statistically representative sample which can be used to test and further develop the theory of compact binary evolution.

C06_009: Evolved planetary systems

(Amornrat Aungwerojwit, Naraesuan U.)

The study of evolved planetary systems is an emerging research field with considerable potential, and our aim is to carry out the first dedicated study of the full range of these systems. This project will significantly contribute to our overall understanding of the formation, architecture, and evolution of planets. We will in particular investigate the tidal disruption of rocky planetesimals and the subsequent formation and evolution of debris discs around white dwarfs through intensive follow-up of WD1145+017, the first white dwarf with detected transits. Our previous TNT observations of this system demonstrate a rapid evolution of the debris field at this white dwarf, providing real-time insight into the physical processes at work. We will also carry out a detailed search for additional systems with photometric transits by obtaining high-time resolution light curves of ~20 white dwarfs with dusty debris discs.

C06_010: Identifying white dwarf-pulsators in interacting binaries

(Amornrat Aungwerojwit, Naraesuan U.)

The study of stellar pulsations, asteroseismology, has the potential to probe the entire interior structure of a star, and very accurate asteroseismological parameter studies have been carried out for single stars. The same method offers an enormous potential to determine the effect that the accretion of mass, angular momentum, and energy has in interacting binaries, and to infer how common envelope evolution affects the stellar structure of the white dwarf that is left behind. However, so far we only know a handful of pulsating white dwarfs in binary stars. Here we propose to use ULTRASPEC on the TNT to increase the number of non-radial pulsators in cataclysmic variables (CVs). This exploratory study is a necessary first step that will be followed by detailed asteroseismological studies once suitable targets have been identified.


C06_011: Radial velocity observations of OB1d association in NGC 1977

(Watunyoo Patwong, NARIT)

Radial velocity observations will be obtained for five stars of the Ori OB1d association in the nebula NGC1977, using the MRES spectrograph with the 2.4 m telescope at Thai National Observatory to measure spectrum. These stars are early spectral type with difference radial velocities. Purpose of this project is to investigate direction of the stars in the association. Effect from Orion molecular cloud, including gravitational force and other will be study.

C06_012: Extended [OIII] emission as a tracer of AGN outflows from narrow-line Seyfert I

(Bovornpratch Vijarnwannaluk, Tohoku U.)

Feedback from active galactic nuclei (AGN) is now a standard ingredient in galaxy formation models, yet the direct characterization of such feedback, e.g., AGN-driven outflows, is scarce. We propose to observe a sample of narrow-line Seyfert I (NLSy I) galaxies at z = 0.3 using deep narrow-band imaging to search for the redshifted, extended OIII emission in the host galaxies and search for potential signatures of galaxy wide outflows. As a pilot study, we propose to observe at least six NLSy I galaxies and constrain the geometry and size of the extended narrow-line region. The narrow-band images will complement deep imaging data from the Subaru Hyper-Suprime Cam (HSC) imaging survey which is currently used to study the host morphology and to estimate stellar masses. Given that the host galaxies are extended out to ~10 kpc we can directly compare the ionized OIII emission with the stellar component.

C06_013: Long-term monitor of the long-period redback pulsar J2129-0429

(Siraprapa Sanpa-arsa, NARIT)

PSR J2129-0429 is a “redback” pulsar binary that belongs to the more general class of “Spiders”, in which a pulsar gradually ablates a low-mass companion orbiting at close distance. Some redbacks called transitional millisecond pulsars have recently been found to occupy a key stage of binary evolution marking the transition from active accretion in a low-mass X-ray binary to a rotation-powered pulsar with an evolved companion. J2129 is the first and only formally identified Spider in which small secular optical changes have been detected so far and, while it is not a proper transitional system, it might give us very important clues about the evolution of these systems. We propose to initiate a bi-annual monitoring campaign in order to 1) track the future behaviour of this system and 2) shed light on the physical mechanism responsible for these secular changes.

C06_014: Atmospheric study of KELT-3b

(Sutthawee Yodmongkol, SUT)

KELT-3b is an exoplanet orbiting around its host star, KELT-3. The host star has an absolute magnitude V = 9.8 and it is a late F star with a mass of 1.278 M, a radius of 1.472 R and effective temperature of 6,306 K (Pepper et al., 2013). As far as we have concerned, there is no report of KELT-3b atmosphere using transit method. KELT-3b is listed to be one of top 10% ranking to be detected atmosphere via transmission spectroscopy technique (Morgan et al. 2018). Moreover, there is no detail study of this planet after its discovery paper. Therefore, we plan to use the TNT to study of KELT-3b with more filter for allow us to obtain detailed physical and also its atmospheric parameters.

C06_015: Transmission spectroscopy of exoplanets

(Supachai Awiphan, NARIT)

Todate, more than 3,500 planets, ranging in size from Earth to larger than Jupiter, have been confirmed by various methods, including over 2,300 by Kepler using the transit method (Morton et al. 2016). In addition to the discovery of new exoplanets, the characterization of planetary interiors and atmospheres is a rapidly developing area. One method that is used to study planetary atmospheres is transmission spectroscopy, which measures the variation of transit depth with wavelength (Seager & Deming 2010). From the transmission spectroscopy technique, the absorption spectrum and the composition of the planetary atmosphere can be deduced. This method has been applied to several transiting exoplanets. During 2013-16 observational seasons, we used the TNT to perform transmission spectroscopy of a hot-Neptune, GJ3470b, which provide a low mean molecular weight (1.08\pm0.20) with high particle abundance at high altitude atmosphere (Awiphan et al. 2016). We currently develop a metric-based target selection approach for selecting exoplanets for their atmospheric studies (Morgan et al. 2018). In this proposal, we plan to use the TNT with ULTRASPEC and the Thai Robotic Telescopes Network (TRTN) to perform transmission spectroscopy observation of exoplanets in order to provide a better understanding of exoplanet atmosphere and statistic of planetary atmosphere.

C06_016: Resolving K2 transiting exoplanet candidates

(Supachai Awiphan, NARIT)

Dilution from nearby stars can have significant implications for the detection and characterization of exoplanets, including triggering false positives and masking the true radii of planets (Matson et al. 2018). For planet candidate hosts with nearby stars unresolved in transit photometry, the light from the stellar companion will dilute the transit signal, causing the planet to appear smaller than it actually is. Exquisite Kepler/K2 photometry has led to the discovery of many new planets and candidates, but the putative host stars are often blended with other nearby stars due to the large pixel scale of the detector. By resolving these stars in transit photometry, the true undiluted transit can be either measured directly or ruled out for the diluting companions, resulting in the identification of the true transit signal host star and an accurate measurement of the planet radius. Here we propose to conduct follow-up transit observations of 10 transiting planet candidates around hosts with nearby stars that are unresolved by Kepler/K2 but at wide enough separations as to be resolvable from the ground. These observations will thus be useful for both the validation of new planets and the accurate determination of their radii.


C06_018: Circumbinary planet around NSVS 14256825 (ULTRASPEC)

(Pranita Sappankun, CMU)

The eclipsing binary (O-C) can be used to detect circumbinary planets, including NSVS 14256825 (Beuermann et al., 2012). However, due to high uncertainty in the data, there are more three proposed third-body model for this system, including one-planet model and two-planet model. In this proposal, we would like to observe including NSVS 14256825 with ULTRASPEC at TNT in order to obtain precise eclipse timing to confirm the confirm the presence of (a) circumbinary planet(s).

C06_019: Stars that might impact the Oort cloud

(David Mkrtichian, NARIT)

This proposal is aimed at finding stars that in the past or future encounters with the Oort cloud. Based on the well-studied case of GJ 710 we expect that stars will penetrate the Oort cloud and trigger a comet shower which increase the flux of long period comets by at least one order of magnitude. This potentially has a significant impact on the Earth in terms of comet showers and even mass extinctions. We request data with MRES to constrain potentially Oort cloud crossing objects that we have discovered in the Gaia DR2 data release. The primary uncertainty in the orbits is the uncertainty of several km/s in radial velocity which we can reduce to around 50 m/s with the proposed MRES observations. This is suffice to strongly constrain the orbits. We have a sample of 211 objects which might plausibly cross the Oort cloud. With two observing runs at either end of the semester, we can observe approximately the brightest 50 of these with close orbits.

C06_020: Spectroscopic studies of FUors/EXors using MRES with Thai National Telescope

(Arpan Ghosh, ARIES)

We propose to carry out optical spectroscopic study of the low mass outbursting (ΔV~3-5 mag.) protostars classified as FUors and EXors and their photometric monitoring; caused by episodic accretion of matter from the circumstellar disc onto the protostar. These outbursts play very crucial role in the final evolution of protostar and protoplanetary disc. In order to understand and model the mechanisms driving these outbursts, we need detailed light curves and evolution of spectral lines. In the present cycle for Thai National Telescope(TNT) we propose to carry out spectroscopic study of FUors/EXors present in the Orion and Cygnus regions followed. Simultaneously we are proposing for time with Thai Remote Telescope(TRT) for photometry. Photometric monitoring will help to measure the transient changes in energy output, generate SEDs while spectrum of Hα, Hβ, etc lines that originate from the accretion column and jets will help us to estimate the accretion rate and fluctuations in them help us to accurately constrain the different trigger mechanisms of outbursts. Optically thin forbidden emission lines will help us to understand the mass loss during this phase, outflow temperature and density and outflow nature. We are obtaining NIR spectra from HCT to study the CO(2-0) ro-vibrational band and the water bands to understand the heating effect of outburst.


C06_021: Circumbinary planet around NSVS 14256825 (MRES)

(Pranita Sappankun, CMU)

The eclipsing binary (O-C) can be used to detect circumbinary planets, including NSVS 14256825 (Beuermann et al., 2012). However, due to high uncertainty in the data, there are more three proposed third-body model for this system, including one-planet model and two-planet model. In this proposal, we would like to observe including NSVS 14256825 with ULTRASPEC at TNT in order to obtain precise eclipse timing to confirm the confirm the presence of (a) circumbinary planet(s).


C06_022: Absolute parameters of spectroscopic binaries

(Pranita Sappankun, CMU)

Two Spectroscopic binary systems of Algol-type were selected in this programme. TW Cas and IM Aur. The purpose were obtained spectral type, plotted a precision radial velocity data and plotted the binary’s light curve, O − C diagrams of eclipsing binaries, determined the orbital parameter in order to investigate the absolute characteristics of the components in a model. There are more propose third-body model for two eclipsing binary stars. In this proposal, We would like to observe the object with ULTRASPEC and MRES at TNT.

C06_024: A test for the single degenerate channel towards type Ia supernovae (spectroscopy)

(Puji Irawati, NARIT)

The progenitors of type Ia supernovae are close binaries containing white dwarfs. Of crucial importance to the evolution of these systems is how much material the white dwarf can stably accrete and grow in mass. This occurs during the super-soft source (SSS) phase. The short duration of this phase means that only a handful of SSS are known. Far more can be learned from the underlying SSS progenitor population of close white dwarf plus F,G,K type binaries. Using the GALEX and LAMOST surveys we have now identified the first large sample of F,G,K stars with significant UV excesses typical of white dwarfs. Follow-up observations at the TNT using MRES and several other telescopes have led us to the discovery of 24 binaries among our sample displaying significant radial velocity variations (published in 2017). Further search using data from LAMOST, RAVE, and TGAS has brought our samples to ~60 systems. Here we apply for 10 nights of observations at the TNT with MRES to measure the orbital periods of these WD+FGK binaries displaying radial velocity and photometric variations in their Catalina light curves. We send our request for photometric follow-up with ULTRASPEC in a separate proposal.

C06_025: Searching for Quasi-Periodic Pulsations in Stellar Flares

(Puji Irawati, NARIT)

To truly understand the link between stellar flares and solar flares, we must first create a solid observational link between the physical processes occurring in each case. Quasi-periodic pulsations (QPPs), have been suggested as a potential means to connect the physics of stellar white light flares to what is observed on the Sun. QPPs with periods between fractions of a second to tens of minutes, are a feature of solar flares that appear to exist in stellar flares, although the shortest periods observed in stellar flares is 20 sec. In white-light stellar flare data, QPPs typically appear as modulations in the decay phase of large flares or super-flares. We propose to carry out a survey for QPPs in high-cadence (<1 sec) observations of stellar flares using ULTRASPEC. Here we apply for 4 nights of observations at the TNT with ULTRASPEC to search for these QPPs in a few selected target known to display frequent flaring events with an expectation of one large flare every 12hrs.

C06_026: Probing the Physics of Accretion Columns in Magnetic CVs

(Puji Irawati, NARIT)

Through observations of Quasi Periodic Oscillations (QPOs) on timescales of a few seconds, the nature of plasma instabilities in accretion columns will be investigated in a selection of Polars. This project will utilize the ULTRASPEC camera at TNO to begin a new epoch of QPO observations, on polars not yet observed for this purpose or with such instrumentation. Understanding the nature of the QPOs (Q-values; Power Density Spectra; orbital phase dependency) will allow for more definitive modelling of magnetically constrained accretion columns. These observations will be combined with laboratory simulations of accretion columns, being conducted by our colleagues using the LULI laser facility, to provide the first combined observational, numerical modelling and experimental study of accretion column physics. We successfully observed several targets although we lost almost half of the allocated time due to weather. In this cycle, we will repeat our observations for target with low SNR and expand our target in this cycle to include several magnetic CVs with different characteristics.

C06_027: High time resolution observations of eclipsing binary systems to investigate possible exoplanets and flickering

(Puji Irawati, NARIT)

We propose to observe few compact eclipsing binaries to confirm the existence of the extrasolar planets orbiting these systems. Our targets are the short period cataclysmic variables and post common-envelope systems, e.g. DP Leo, UZ For, HU Aqr, which are known or suspected to host circumbinary planets . We will observe them in fast time resolution (1-3sec in subwindow mode) using ULTRASPEC. We will focus our attention on the eclipses, with special interest during the ingress and egress, to investigate the deviation in the (O-C) diagrams due to the light time travel effect or the actual gravitational effects. Our result will play a significant role in determining the model of planetary systems in binary. These data will be combined with the result from several other telescopes (Thai Robotic Telescopes, Rozhen telescope, 1m-robotic at Tubitak Obs.) and the data of other instrument (OPTIMA). Our data obtained from the 2.4m-TNT in May 2017 definitely challenges previous results on the existence of Jupiter-sized exoplanets in this system. Therefore, further follow-up observation are necessary to confirm our findings on HU Aqr and other similar systems.

C06_029: Stellar occultation by the Centaurs and Trans-Neptunian Objects

(Puji Irawati, NARIT)

We propose to observe stellar occultations by Trans-Neptunian Objects (TNOs) and Centaurs, using the 2.4m telescope with ULTRASPEC (fast mode). These objects constitute a large population in the outer regions of the Solar System which provides crucial clues to the formation and evolution of our own planetary system. Yet, they are still poorly known due to their faintness and small angular sizes. Goals are (1) measure size of TNO at km-accuracy and derive density for those whose mass is known; (2) discover and monitor atmosphere around largest objects, with a few nanobar sensitivity; (3) discover and monitor rings around some TNOS. Potential candidates during Cycle 6 are (among others): Chaos and Bienor. The drastic improvement provided by the Gaia DR1 catalog will make predictions 3-4 times more accurate than previously done.


C06_030: Tracking the optical variability of ultraluminous X-ray sources

Wasutep Luangtip, SWU)

Ultraluminous X-ray sources (ULXs) are extra-galactic, non-nuclear point sources, with X-ray luminosities in excess of the Eddington limit for a ∼ 10 solar-mass (M⊙) black hole. It is thought that ULXs are powered by accreting objects, especially black holes; however, due to their extreme brightness, the mass of compact objects powering ULXs is still a topic of active debate. In this work, we propose to use the TNT ULTRASPEC camera to study the optical variability of ULXs. Based on the results from cycles 4 & 5, we found that the ULX Holmberg IX X-1 shows the strongest variability (up to ~1.4 mag in g' band) among the other observed ULXs. In this cycle, we request observing time of 10 full nights - divided into 2 slots of 5 consecutive nights - to constrain the period that the ULX Holmberg IX X-1 varies over. Using the data obtained, if the period is detected, we aim to estimate the mass of compact object powering the ULXs.

C06_031: Spectroscopic studies of pre-main sequence stars

(Tirthendu Sinha, ARIES)

With this proposal we are requesting for 3 nights in 2.4m Thai National Telescope (TNT) to carry out optical spectroscopic study of several pre-main sequence stars. During early evolution of young stars they undergo different physical processes such as accretion, outflow, stellar wind etc. The presence of emission and absorption lines in the stellar spectra reveals those physical process and helps to get an quantitative measure of different parameters. For example Hydrogen Blamer series (Hα, Hβ, Hγ), HeI,OI, CaII lines are useful to calculate the accretion rate whereas the flux ratio of forbidden lines like [S II ] λ6716/λ6731 is a good tracer of outflow density. Using the Medium Resolution fiber-fed Echelle Spectrograph (MRES) we will be able to resolved some closely spaced lines(OI triplet, finer absorption lines in Hα P Cygni profile etc. ) and study finer details. Once the spectral type of a star is known it is useful to estimate luminosity, surface temperature, extinction and distance which makes the interpretation of physical processes more accurate. Our sample contains pre-main sequence stars from two young open clusters. In our study with the clusters we have found some of these stars to be variables. It will be interesting to study their spectroscopic features.

C06_032: A study of atmosphere and properties of HAT-P-36b

(Patcharawee Munsaket, SUT)

HAT-P-36b is a hot-Jupiter exoplanet orbit around host star name HAT-P-36 with a short orbital period P = 1.32735 days (G. À. Bakos et al. 2012). The exoplanet was discovered by the Hungarian-made Automated Telescope Network (HATNet) Exoplanet Survey. The host star has an equal mass to the Sun’s mass and a roughly equal Sun’s radius. The exoplanet has a high surface temperature, so it has a chance to study the atmosphere of this exoplanet using the transmission spectroscopy technique. Transmission spectroscopy technique has to use the set of data from many filters. From the discovery paper, only one full transit light curve is obtained from KeplerCam at the FLWO 1.2m telescope. Therefore, a full transit light curve from the TNT with ULTRASPEC in several filters (u’, g’, i’, r’ and z’) should provide a better data for planetary parameters and atmospheric studies.


Follow-up observation of ellipsoidal binaries using 2.4m Thai National Telescope

(Kittipong Wangnok, SUT)

We propose to do follow-up photometric observations on ellipsoidal binaries from the Catalina Sky Survey (CSS) and the Siding Spring Survey (SSS). These systems were published by Drake et al. in 2014 and 2017. In this proposal, we have selected several new ellipsoidal binaries with orbital period < 7 hr to investigate and determine the stellar and the orbital parameters. From our previous observations, we were able to obtain light curves of CSS J0703+3442 and CSS J1052+2157 in z’ and i’ Rlters. In addition, SSS J1526-2500 was observed in different Rlters (r’, i’, and z’ Rlters). The preliminary stellar model for SSS J1526-2500 is done using Binary Maker3 (BM3) and JKTEBOP code. In this proposal, we request to do more observation in various Rlters and to compare with previous observation. The stellar and orbital parameters will be determined using JKTEBOP code and Binary Maker3.0 (BM3) software.


Spectroscopic observation of ellipsoidal binaries

(Kittipong Wangnok, SUT)

We propose to do follow-up photometric observations on ellipsoidal binaries from the Catalina Sky Survey (CSS) and the Siding Spring Survey (SSS). These systems were published by Drake et al. in 2014 and 2017. In this proposal, we have selected several new ellipsoidal binaries with orbital period < 7 hr to investigate and determine the stellar and the orbital parameters. From our previous observations, we were able to obtain light curves of CSS J0703+3442 and CSS J1052+2157 in z’ and i’ Rlters. In addition, SSS J1526-2500 was observed in different Rlters (r’, i’, and z’ Rlters). The preliminary stellar model for SSS J1526-2500 is done using Binary Maker3 (BM3) and JKTEBOP code. In this proposal, we request to do more observation in various Rlters and to compare with previous observation. The stellar and orbital parameters will be determined using JKTEBOP code and Binary Maker3.0 (BM3) software.


Vetting TESS exoplanet candidates around A and M stars

(Petchara Pattarakijwanich, Mahidol U.)

The Transiting Exoplanet Survey Satellite (TESS) is the next revolution in the Aeld of exoplanets. It is surveying the entire sky for planet candidates around bright stars that are suitable for further characterizations. During its Arst year of operations, TESS will And thousands of planet candidates in the Southern ecliptic hemisphere orbiting stars across the HR diagram. We will use TNT/MRES to target Jovian and Neptune-sized planet candidates orbiting A and M stars to understand how planet occurrence rate is affected by the mass of the host star. The MRES observations will help us estimate the false-positive rate of the TESS giant planet candidate sample. Our observations will also be used to select the optimal planet candidates for further follow-up with precision radial velocity facilities on 4-8 m class facilities.