arXiv subjects

A. Hanslmeier

Publications and source records attributed to A. Hanslmeier.

At least 19 recordsLinked to original sources

arXiv2026

Modeling brightness temperature of sunspots using ALMA single-dish observations

We model sunspot brightness temperature in the wavelength range 0.3-10mm using the Atacama Large Millimeter/submillimeter Array (ALMA) single-dish measurements together with other instruments. Our modeling idea starts from an existing model, the 1D semi-empirical Avrett-Tian-Landi-Curdt-W\"ulser (ATLCW) model for sunspots. The original model is then modified in density and temperature with a constant factor over all heights. A least-square fit in both density and temperature to the observed values yields an improved model for sunspot brightness temperature. Observations show that sunspots are darker than QS at wavelengths below 2 mm and brighter beyond, while fitting of the ATLCW sunspot model imply that sunspots should be darker than QS over the entireALMArange. The best-fitted sunspot brightness temperature profiles resulted in 3.6-4.0 times lower sunspot density compared to the original sunspot ATLCW model, or 1.4-1.8 times higher density compared to QS. The temperature came out around 1.2 times higher than the original ATLCW predictions for sunspots, or 1.2 times lower than QS temperature. Even with improved density and temperature parameters, the remaining discrepancy between the bestfitted models and observations indicated that additional improvements are needed in the ATLCW model and modeling assumptions.

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arXiv2025

Modeling brightness temperature of prominences on the solar disk using ALMA single-dish observations

Prominences (PRs) are among the most common solar phenomena, yet their full physical picture, particularly their chromospheric mm emission, remains incomplete. The new Atacama Large Millimeter/submillimeter Array (ALMA) presents an opportunity to study PRs at mm and sub-mm wavelengths through a combination of measurements and theoretical modeling. We utilize ALMA single-dish measurements alongside data from other radio instruments to model the PR brightness temperature through adaptation and modification the 1D semi-empirical Avrett-Tian-Landi-Curdt-W\"ulser (ATLCW) quiet-Sun (QS) model. The calculated and measured PR brightness temperatures were found to be lower than the measured QS value and predictions from the unperturbed ATLCW QS model across the ALMA wavelength range, consistent with PRs appearing in absorption. The PR density was found to be 60 - 163 times higher and temperature 155 - 163 times lower than the QS level, aligning with previous measurements. A key finding emerged with the non-hydrostatic equilibrium assumption, yielding a more physically consistent PR brightness temperature. This suggests that PR stability is most likely maintained by its magnetic field obeying magnetostatic conditions rather than by pure hydrostatic equilibrium, supporting recent studies. Additionally, our results confirm that thermal bremsstrahlung is the dominant radiation mechanism for PRs at mm and sub-mm wavelengths.

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arXiv2025

Coronal bright point statistics II. Magnetic polarities and mini loops

Context. The solar corona maintains temperatures of a million Kelvin or more. The plasma heating mechanisms responsible for these extreme temperatures are still unclear. Large regions of magnetic activity in the photosphere cause extreme ultraviolet (EUV) emission in the corona. Even smaller regions with bipolar and multipolar magnetic fields can generate coronal bright points (CBPs). Aims. We performed a statistical analysis of 346 CBPs. We used Solar Dynamics Observatory (SDO) images to track CBPs on a continuous basis. Therefore, we were able to collect a database of information on the CPB's lifetime, shape, polarity, flux emergence, and merging behavior, as well as their magnetic evolution, using the SDO Helioseismic and Magnetic Imager (SDO-HMI) instrument. Methods. We searched the SDO data archive for the longest continuous interval of uninterrupted observations in 2015. The longest such interval contains 12 consecutive days of full-disk images from the EUV channels of the SDO-AIA instrument. To analyze the properties of CBPs, we employed an automated tracking algorithm to follow the evolution of the CBPs. Furthermore, we manually checked the shape, underlying magnetic polarities, and merging behavior of each CBP. Results. We provide statistics on the magnetic polarity, emergence, and merging of CBPs. We established a relationship between the CBP's merging behavior and both its shape and magnetic polarities. Brighter CBPs are visible in all SDO-AIA channels and exhibit strong radiative energy losses. The category of CBPs with a bipolar field has the highest probability of being emissive in all SDO-AIA channels. The majority of CBPs have two opposite polarities below them. Conclusions. The merging of two CBPs is an unusual phenomenon that is related to complex multipolar magnetic regions. Moreover, loop-shaped CBPs usually appear above bipolar fields... (see full abstract in pdf)

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arXiv2025

Improving the stellar age determination through joint modeling of binarity and asteroseismology -- Grid modeling of the seismic red-giant binary KIC 9163796

Context. Typical uncertainties of ages determined for single star giants from isochrone fitting using single-epoch spectroscopy and photometry without any additional constraints are 30-50 %. Binary systems, particularly double-lined spectroscopic (SB2) binaries, provide an opportunity to study the intricacies of internal stellar physics and better determine stellar parameters, particularly the stellar age. Aims. By using the constraints from binarity and asteroseismology, we aim to obtain precise age and stellar parameters for the red giant-subgiant binary system KIC 9163796, a system with a mass ratio of 1.015 but distinctly different positions in the Hertzsprung-Russell diagram (HRD). Methods. We compute a multidimensional model grid of individual stellar models. From different combinations of figures of merit, we use the constraints drawn from binarity, spectroscopy, and asteroseismology to determine the stellar mass, chemical composition, and age of KIC 9163796. Results. Our combined-modeling approach leads to an age estimation of the binary system KIC 9163796 of 2.44$^{+0.25}_{-0.20}$ Gyr, which corresponds to a relative error in the age of 9 %. Furthermore, we found both components exhibiting equal initial helium abundance of 0.27 to 0.30, significantly higher than the primordial helium abundance, and an initial heavy metal abundance below the spectroscopic value. The masses of our models are in agreement with masses derived from the asteroseismic scaling relations. Conclusions. By exploiting the unique, distinct positions of KIC 9163796, we successfully demonstrated that combining asteroseismic and binary constraints leads to a significant improvement of precision in age estimation, that have a relative error below 10% for a giant star.

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arXiv2024

Calculated brightness temperatures of solar structures compared with ALMA and Metsähovi measurements

The Atacama Large Millimeter/submillimeter Array (ALMA) allows for solar observations in the wavelength range of 0.3$-$10 mm, giving us a new view of the chromosphere. The measured brightness temperature at various frequencies can be fitted with theoretical models of density and temperature versus height. We use the available ALMA and Metsähovi measurements of selected solar structures (quiet sun (QS), active regions (AR) devoid of sunspots, and coronal holes (CH)). The measured QS brightness temperature in the ALMA wavelength range agrees well with the predictions of the semiempirical Avrett$-$Tian$-$Landi$-$Curdt$-$Wülser (ATLCW) model, better than previous models such as the Avrett$-$Loeser (AL) or Fontenla$-$Avrett$-$Loeser model (FAL). We scaled the ATLCW model in density and temperature to fit the observations of the other structures. For ARs, the fitted models require 9%$-$13% higher electron densities and 9%$-$10% higher electron temperatures, consistent with expectations. The CH fitted models require electron densities 2%$-$40% lower than the QS level, while the predicted electron temperatures, although somewhat lower, do not deviate significantly from the QS model. Despite the limitations of the one-dimensional ATLCW model, we confirm that this model and its appropriate adaptations are sufficient for describing the basic physical properties of the solar structures.

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arXiv2023

Constraining stellar and orbital co-evolution through ensemble seismology of solar-like oscillators in binary systems -- A census of oscillating red-giants and main-sequence stars in Gaia DR3 binaries

Binary systems constitute a valuable astrophysics tool for testing our understanding of stellar structure and evolution. Systems containing a oscillating component are interesting as asteroseismology offers independent parameters for the oscillating component that aid the analysis. About 150 of such systems are known in the literature. To enlarge the sample of these benchmark objects, we crossmatch the Two-Body-Orbit Catalogue (TBO) of Gaia DR3, with catalogs of confirmed solar-like oscillators on the main-sequence and red-giant phase from NASA Kepler and TESS. We obtain 954 new binary system candidates hosting solar-like oscillators, of which 45 and 909 stars are on the main sequence and red-giant, resp., including 2 new red giants in eclipsing systems. 918 oscillators in potentially long-periodic systems are reported. We increase the sample size of known solar-like oscillators in binary systems by an order of magnitude. We present the seismic properties of the full sample and conclude that the grand majority of the orbital elements in the TBO is physically reasonable. 82% of all TBO binary candidates with multiple times with APOGEE are confirmed from radial-velocity measurement. However, we suggest that due to instrumental noise of the TESS satellite the seismically inferred masses and radii of stars with $ν_\textrm{max}$$\lesssim$30$μ$Hz could be significantly overestimated. For 146 giants the seismically inferred evolutionary state has been determined and shows clear differences in their distribution in the orbital parameters, which are accounted the accumulative effect of the equilibrium tide acting in these evolved binary systems. For other 146 systems hosting oscillating stars values for the orbital inclination were found in the TBO. From testing the TBO on the SB9 catalogue, we obtain a completeness factor of 1/3.

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arXiv2023

Coronal bright point statistics I. Lifetime, shape, and coronal co-rotation

Context. The corona of the Sun is the part of the solar atmosphere with temperatures of over one million Kelvin, which needs to be heated internally in order to exist. This heating mechanism remains a mystery; we see large magnetically active regions in the photosphere lead to strong extreme UV (EUV) emission in the corona. On much smaller scales (on the order of tens of Mm), there are bipolar and multipolar regions that can be associated with evenly sized coronal bright points (CBPs). Aims. Our aim was to study the properties of CBPs in a statistical sense and to use continuous data from the SDO spacecraft, which makes it possible to track CBPs over their whole lifetime. Furthermore, we tested various rotation-speed profiles for CBPs in order to find out if the lower corona is co-rotating with the photosphere. Then we compiled a database with about 346 CBPs together with information of their sizes, shapes, appearance and disappearance, and their visibility in the EUV channels of the AIA instrument. We want to verify our methods with similar previous studies. Methods. We used the high-cadence data of the largest continuous SDO observation interval in 2015 to employ an automated tracking algorithm for CBPs. Some of the information (e.g., the total lifetime, the characteristic shape, and the magnetic polarities below the CBPs) still requires human interaction. Results. In this work we present statistics on fundamental properties of CBPs along with some comparison tables that relate, for example, the CBP lifetime with their shape. CBPs that are visible in all AIA channels simultaneously seem to be brighter in total and also have a stronger heating, and hence a higher total radiation flux. We compared the EUV emission visibility in different AIA channels with the CBP's shape and lifetime. ... (full version see pdf)

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arXiv2023

Revealing the structure of the lensed quasar Q 0957+561 III. Constraints on the size of the broad-line region

Our aim is to examine the size, kinematics, and geometry of the broad-line region (BLR) in the double-lensed quasar Q 0957+561 by analyzing the impact of microlensing on various rest-frame ultraviolet broad-emission lines (BELs). We explore the influence of intrinsic variability and microlensing on the C IV, C III], and Mg II emission lines through multiple spectroscopic observations taken between April 1999 and January 2017. By utilizing the line cores as a reference for no microlensing and correcting for the long time delay between the images, we estimate the sizes of the regions emitting the broad-line wings using a Bayesian approach. Our study of the microlensing amplitudes between the lensed images of the quasar Q 0957+561 reveals differing sizes of the regions emitting the three prominent BELs C IV, C III], and Mg II. The strength of the differential microlensing indicates that the high-ionization line C IV arises from a compact inner region of the BLR with a half-light radius of $R_{1/2} \gtrsim 16.0$ lt-days, which represents a lower limit on the overall size of the BLR and is comparable to the size of the region emitting the r-band continuum in this system. A somewhat larger size of $R_{1/2}\gtrsim 44$ lt-days is obtained for the semi-forbidden line C III]. Microlensing has a weak impact on the lower-ionization line Mg II, which is emitted from a region with a half-light radius of $R_{1/2} \gtrsim 50$ lt-days. These findings suggest that the BEL regions may have distinct geometries and kinematics, with the more extended ones being spherically symmetric, and the most compact ones being nonspherical, with motions likely confined to a plane.

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arXiv2023

Exploring magnetic field properties at the boundary of solar pores: A comparative study based on SDO-HMI observations

The Sun's magnetic fields play an important role in various solar phenomena. Solar pores are regions of intensified magnetic field strength compared to the surrounding photospheric environment, and their study can help us better understand the properties and behaviour of magnetic fields in the Sun. Up to now, there exists only a single study on magnetic field properties at the boundary region of a pore. Therefore, the main goal of this work is to increase the statistics of magnetic properties determining the pore boundary region. We analyse six solar pores using data from the Helioseismic and Magnetic Imager instrument on board the Solar Dynamics Observatory. We apply image processing techniques to extract the relevant features of the solar pores and determine the boundary conditions of the magnetic fields. We find the maximal vertical magnetic field values on the boundaries of the studied solar pores to range from 1400~G to 1600~G, with a standard deviation between 7.8\% and 14.8\%. These values are lower than those reported in the mentioned preceding study. However, this can be explained by differences in spatial resolution as well as the type of data we used. The vertical magnetic field is an important factor in determining the boundary of solar pores, and it plays a more relevant role than the intensity gradient. The obtained information will be useful for future studies on the formation and evolution of magnetic structures of the Sun. Additionally, this study highlights the importance of high spatial resolution data for the purpose of accurately characterising the magnetic properties of solar pores.

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arXiv2022

Variation in solar differential rotation and activity in the period 1964-2016 determined by the Kanzelhöhe data set

We determined the differential rotation (DR) parameters $A$ and $B$ (corresponding to the equatorial rotation velocity and the gradient of the solar DR) by tracing sunspot groups in sunspot drawings of the Kanzelhöhe Observatory for Solar and Environmental Research (KSO; 1964-2008, for solar cycles (SC) 20-23) and KSO white-light images (2009-2016, for SC 24). We used different statistical methods and approaches to analyse cycle related variations, solar cycle phase-related variations and long-term variations of the DR. $A$ and $B$ show statistically significant periodic variability. The changes in $A$ related to solar cycle phase are in accordance with previously reported theoretical and experimental results (higher $A$ during solar minimum, lower $A$ during the maximum of activity), while changes in $B$ differ from the theoretical predictions as we observe more negative values of $B$, that is, a more pronounced DR during activity maximum. The main result of this paper for the long-term variations in $A$ is the detection of a phase shift between the activity flip (in the 1970s) and the equatorial rotation velocity flip (in the early 1990s). During this time period both $A$ and activity show a secular decreasing trend, indicating their correlation. Therefore, the theoretical model fails in the phase-shift time period that occurs after the modern Gleissberg maximum, while in the time period thereafter (after the 1990s), theoretical and experimental results are consistent. The long-term variations in $B$ in general yield an anticorrelation of $B$ and activity, as a rise of $B$ is observed during the entire time period (1964-2016) we analysed, during which activity decreased. We study for the first time the variation in solar DR and activity based on 53 years of KSO data. Our results agree well with the results related to the solar cycle phase from corona observations.

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arXiv2022

A prediction for the 25th solar cycle maximum amplitude

The minimum - maximum method, belonging to the precursor class of the solar activity forecasting methods, is based on a linear relationship between relative sunspot number in the minimum and maximum epochs of solar cycles. In the present analysis we apply a modified version of this method using data not only from the minimum year, but also from a couple of years before and after the minimum. The revised 13-month smoothed monthly total sunspot number data set from SILSO/SIDC is used. Using data for solar cycle nos. 1-24 the largest correlation coefficient (CC) is obtained when correlating activity level 3 years before solar cycle minimum with the subsequent maximum (CC = 0.82), independent of inclusion or exclusion of the solar cycle no. 19. For the next solar maximum of the cycle no. 25 we predict: Rmax = 121 +- 33. Our results indicate that the next solar maximum (of the cycle no. 25) will be of the similar amplitude as the previous one, or even something lower. This is in accordance with the general middle-term lowering of the solar activity after the secular maximum in the 20th century and consistent with the Gleissberg period of the solar activity. The reliability of the 3 years before the minimum predictor is experimentally justified by the largest correlation coefficient and verified with the Student t-test. It is satisfactorily explained with the two empirical well-known findings: the extended solar cycle and the Waldmeier effect. Finally, we successfully reproduced the maxima of the last four solar cycles, nos. 21-25, using the 3 years before the minimum method.

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arXiv2021

Prominence instability and CMEs triggered by massive coronal rain in the solar atmosphere

Triggering process for prominence instability and consequent CMEs is not fully understood. Prominences are maintained by the Lorentz force against the gravity, therefore reduction of the prominence mass due to the coronal rain may cause the change of the force balance and hence destabilisation of the structures. We aim to study the observational evidence of the influence of coronal rain on the stability of prominence and subsequent eruption of CMEs. We used the simultaneous observations from AIA/SDO and SECCHI/STEREO spacecrafts from different angles to follow the dynamics of prominence/filaments and to study the role of coronal rain in their destabilisation. Three different prominences/filaments observed during years 2011-2012 were analysed using observations acquired by SDO and STEREO. In all three cases massive coronal rain from the prominence body led to the destabilisation of prominence and subsequently to the eruption of CMEs. The upward rising of prominences consisted in the slow and the fast rise phases. The coronal rain triggered the initial slow rise of prominences, which led to the final instability (the fast rise phase) after 18-28 hours in all cases. The estimated mass flux carried by coronal rain blobs showed that the prominences became unstable after 40 \% of mass loss. We suggest that the initial slow rise phase was triggered by the mass loss of prominence due to massive coronal rain, while the fast rise phase, i.e. the consequent instability of prominences, was caused by the torus instability and/or magnetic reconnection with overlying coronal field. Therefore, the coronal rain triggered the instability of prominences and consequent CMEs. If this is the case, then the coronal rain can be used to predict the CMEs and hence to improve the space weather predictions.

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arXiv2021

Revealing the structure of the lensed quasar Q 0957+561: I. Accretion disk size

We aim to use signatures of microlensing induced by stars in the foreground lens galaxy to infer the size of the accretion disk in the gravitationally lensed quasar Q 0957+561. The long-term photometric monitoring of this system (which so far has provided the longest available light curves of a gravitational lens system) permits us to evaluate the impact of uncertainties on our recently developed method (controlled by the distance between the modeled and the experimental magnitude difference histograms between two lensed images), and thus to test the robustness of microlensing-based disk-size estimates. We analyzed the well-sampled 21-year GLENDAMA optical light curves of the double-lensed quasar and studied the intrinsic and extrinsic continuum variations. Using accurate measurements for the time delay between the images A and B, we modeled and removed the intrinsic quasar variability, and from the statistics of microlensing magnifications we used a Bayesian method to derive the size of the region emitting the continuum at 2558 angstroms. Analyses of the Q 0957+561 R-band light curves show a slow but systematic increase in the brightness of the B relative to the A component during the past ten years. The relatively low strength of the magnitude differences between the images indicates that the quasar has an unusually big optical accretion disk of half-light radius $R_{1/2} = 17.6 \pm 6.1 \sqrt{M/0.3M_\odot}$ lt-days.

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arXiv2021

Revealing the structure of the lensed quasar Q 0957+561: III. SMBH mass via gravitational redshift

We intend to use the impact of microlensing on the Fe III emission line blend along with a measure of its gravitational redshift to estimate the mass of the quasar's central supermassive black hole (SMBH). We fit the Fe III feature in multiple spectroscopic observations between 2008 and 2016 of the gravitationally lensed quasar Q 0957+561 with relatively high signal-to-noise ratios (at the adequate wavelength). Based on the statistics of microlensing magnifications, we used a Bayesian method to derive the size of its emitting region. The Fe III spectral feature appears systematically redshifted in all epochs of observation by a value of 17 angstroms on average. We find clear differences in the shape of the Fe III line blend between images A and B. Measuring the strength of those magnitude differences, we conclude that this blend may arise from a region of half-light radius of 15 lt-days, which is in good agreement with the accretion disk dimensions for this system. We obtain a mass for the central SMBH of (1.5 +/- 0.5) x 10^9 solar masses, consistent within uncertainties with previous mass estimates based on the virial theorem. The relatively small uncertainties in the mass determination (< 35%) make this method a compelling alternative to other existing techniques (e.g., the virial plus reverberation mapping based size) for measuring black hole masses. Combining the Fe III redshift-based method with the virial, we estimate a virial factor in the 1.2 to 1.7 range for this system.

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arXiv2021

Microlensing of the broad emission lines in 27 gravitationally lensed quasars. Broad line region structure and kinematics

We aim to study the structure and kinematics of the broad line region (BLR) of a sample of 27 gravitationally lensed quasars with up to five different epochs of observation. This sample is composed of ~100 spectra from the literature plus 22 unpublished spectra of 11 systems. We measure the magnitude differences in the broad emission line (BEL) wings and statistically model the distribution of microlensing magnifications to determine a maximum likelihood estimate for the sizes of the C IV, C III], and Mg II emitting regions. The BELs in lensed quasars are expected to be magnified differently owing to the different sizes of the regions from which they originate. Focusing on the most common BELs in our spectra (C IV, C III], and Mg II), we find that the low-ionization line Mg II is only weakly affected by microlensing. In contrast, the high-ionization line C IV shows strong microlensing in some cases, indicating that its emission region is more compact. Thus, the BEL profiles are deformed differently depending on the geometry and kinematics of the corresponding emitting region. We detect microlensing in either the blue or the red wing (or in both wings with different amplitudes) of C IV in more than 50% of the systems and find outstanding asymmetries in the wings of QSO 0957+561, SDSS J1004+4112, SDSS J1206+4332, and SDSS J1339+1310. This observation indicates that the BLR is, in general, not spherically symmetric and supports the existence of two regions in the BLR, one insensitive to microlensing and another that only shows up when it is magnified by microlensing.

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arXiv2021

Kink instability of triangular jets in the solar atmosphere

It is known that hydrodynamic triangular jets are unstable to antisymmetric kink perturbations. The inclusion of magnetic field may lead to the stabilisation of the jets. Jets and complex magnetic fields are ubiquitous in the solar atmosphere, which suggests the possibility of the kink instability in certain cases. The aim of the paper is to study the kink instability of triangular jets sandwiched between magnetic tubes/slabs and its possible connection to observed properties of the jets in the solar atmosphere. A dispersion equation governing the kink perturbations is obtained through matching of analytical solutions at the jet boundaries. The equation is solved analytically and numerically for different parameters of jets and surrounding plasma. The analytical solution is accompanied by a numerical simulation of fully nonlinear MHD equations for a particular situation of solar type II spicules. MHD triangular jets are unstable to the dynamic kink instability depending on the Alfven Mach number (the ratio of flow to Alfven speeds) and the ratio of internal and external densities. When the jet has the same density as the surrounding plasma, then only super Alfvenic flows are unstable. However, denser jets are unstable also in sub Alfvenic regime. Jets with an angle to the ambient magnetic field have much lower thresholds of instability than field-aligned flows. Growth times of the kink instability are estimated as 6-15 min for type I spicules and 5-60 s for type II spicules matching with their observed life times. Numerical simulation of full nonlinear equations shows that the transverse kink pulse locally destroys the jet in less than a minute in the conditions of type II spicules. Dynamic kink instability may lead to full breakdown of MHD flows and consequently to observed disappearance of spicules in the solar atmosphere.

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arXiv2020

A census of Coronal Mass Ejections on solar-like stars

Coronal Mass Ejections (CMEs) may have major importance for planetary and stellar evolution. Stellar CME parameters, such as mass and velocity, have yet not been determined statistically. So far only a handful of stellar CMEs has been detected mainly on dMe stars using spectroscopic observations. We therefore aim for a statistical determination of CMEs of solar-like stars by using spectroscopic data from the ESO phase 3 and Polarbase archives. To identify stellar CMEs we use the Doppler signal in optical spectral lines being a signature of erupting filaments which are closely correlated to CMEs. We investigate more than 3700 hours of on-source time of in total 425 dF-dK stars. We find no signatures of CMEs and only few flares. To explain this low level of activity we derive upper limits for the non detections of CMEs and compare those with empirically modelled CME rates. To explain the low number of detected flares we adapt a flare power law derived from EUV data to the Hα regime, yielding more realistic results for Hα observations. In addition we examine the detectability of flares from the stars by extracting Sun-as-a-star Hα light curves. The extrapolated maximum numbers of observable CMEs are below the observationally determined upper limits, which indicates that the on-source times were mostly too short to detect stellar CMEs in Hα. We conclude that these non detections are related to observational biases in conjunction with a low level of activity of the investigated dF-dK stars.

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arXiv2020

The BRITE-SONG of Aldebaran -- Stellar Music in three voices

Solar-like oscillations in red-giant stars are now commonly detected in thousands of stars with space telescopes such as the NASA Kepler mission. Parallel radial velocity and photometric measurements would help to better understand the physics governing the amplitudes of solar-like oscillators. Yet, most target stars for space photometry are too faint for light-demanding ground-based spectroscopy. The BRITE Constellation satellites provide a unique opportunity of two-color monitoring of the flux variations of bright luminous red giants. Those targets are also bright enough to be monitored with high-resolution spectrographs on small telescopes, such as the SONG Network. In these proceedings, we provide a first overview of our comprehensive, multi-year campaign utilizing both BRITE and SONG to seismically characterize Aldebaran, one of the brightest red giants in the sky. Because luminous red giants can be seen at large distances, such well-characterized objects will serve as benchmark stars for galactic archeology.

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