Method for Spot-Detection on Solar-like Stars

Silva, Adriana V. R.

doi:10.1017/s007418090018235x

Cited by 4 publications

(17 citation statements)

References 11 publications

(16 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…By modelling the flares using the transit model from Silva (2003) (described in 2.1, we found an energy release of E = 2 × 10 33 ergs for the flare in transit 30th, E = 1.8 × 10 35 ergs for transit 48th, and E = 1.2 × 10 33 ergs for transit 67th. These values are within the energy range found for superflares (∼ 10 33 -10 38 erg) (Karoff et al 2016).…”

Section: Resultsmentioning

confidence: 95%

“…In this work, we characterise the flares present in the transit lightcurves of Kepler-96 using the transit model proposed by Silva (2003). This model simulates a star with quadratic limb darkening as a 2D image and the planet is assumed to be a dark disk with radius R p /R star , where R p is the radius of the planet and R star is the radius of the host star.…”

Section: Methodsmentioning

confidence: 99%

“…From the 86 transits detected, three of them (30th, 48th, and 67th) show flare signatures, and in particular transit 48th has a high intensity flare that causes an increase of 4% in the total luminosity flux of the star. We have modelled the flare using the transit model described in Silva (2003), in which a stellar flare is added to the disk of the star outside the planet transit band. A gaussian profile was chosen to model the flare in time, t, as described below:…”

Section: Methodsmentioning

confidence: 99%

“…Here, we analyse the flares of Kepler-96 using the transit model developed by Silva (2003). This model allows the addition of stellar features such as spots or flares in the simulation.…”

Section: Introductionmentioning

confidence: 99%

“…Section 2 explains the model adopted in this work for simulating transits and shows the different situations of flare detection within planetary transits. The results for the flares parameters using the transit model of Silva (2003) are shown in Section 2.2. The biological impact of the flaring UV flux for life either on the surface or in the ocean of the hypothetical planet in the HZ is evaluated in Section 3.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Superflare Ultraviolet Impact on Kepler-96 System: A Glimpse of Habitability When the Ozone Layer First Formed on Earth

Estrela

Válio

2018

Astrobiology

View full text Add to dashboard Cite

Kepler-96 is an active solar-type star harboring a Super-Earth planet in close orbit. Its age of 2.3 gigayears is the same as the Sun when there was a considerable increase of oxygen in Earth's atmosphere due to micro-organisms living in the ocean. We present the analysis of superflares seen on the transit light curves of Kepler-96b. The model used here simulates the planetary transit in a flaring star. By fitting the observational data with this model, it is possible to infer the physical properties of the flares, such as their duration and the energy released. We found three flares within the energy range of superflares, where the biggest superflare observed was found to have an energy of 1.81 × 10 J (1.81 × 10 ergs). The goal is to analyze the biological impact of these superflares on a hypothetical Earth in the habitable zone of Kepler-96, assuming this planet has protection through different scenarios: an Archean and present-day atmospheres. Also, we compute the attenuation of the flare ultraviolet (UV) radiation through an Archean ocean. The conclusion is that considering the increase in the UV flux by the strongest superflare emission, Escherichia coli and Deinococcus radiodurans could survive on the surface of the planet only if there was an ozone layer present on the planet atmosphere. However, they could escape from the hazardous UV effects at a depth of 28 and 12 m below the ocean surface, respectively. For smaller superflares contribution, D. radiodurans could survive in the surface even in an Archean atmosphere with no ozone.

show abstract

Section: Resultsmentioning

confidence: 95%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

“…Here, we analyse the flares of Kepler-96 using the transit model developed by Silva (2003). This model allows the addition of stellar features such as spots or flares in the simulation.…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Superflare Ultraviolet Impact on Kepler-96 System: A Glimpse of Habitability When the Ozone Layer First Formed on Earth

Estrela

Válio

2018

Astrobiology

View full text Add to dashboard Cite

show abstract

Formation, Habitability, and Detection of Extrasolar Moons

et al. 2014

View full text Add to dashboard Cite

The diversity and quantity of moons in the Solar System suggest a manifold population of natural satellites exist around extrasolar planets. Of peculiar interest from an astrobiological perspective, the number of sizable moons in the stellar habitable zones may outnumber planets in these circumstellar regions. With technological and theoretical methods now allowing for the detection of sub-Earth-sized extrasolar planets, the first detection of an extrasolar moon appears feasible. In this review, we summarize formation channels of massive exomoons that are potentially detectable with current or near-future instruments. We discuss the orbital effects that govern exomoon evolution, we present a framework to characterize an exomoon's stellar plus planetary illumination as well as its tidal heating, and we address the techniques that have been proposed to search for exomoons. Most notably, we show that natural satellites in the range of 0.1-0.5 Earth mass (i) are potentially habitable, (ii) can form within the circumplanetary debris and gas disk or via capture from a binary, and (iii) are detectable with current technology.

show abstract

Superflares and Starspots: when size does not matter

Araújo

Válio

2021

Preprint

View full text Add to dashboard Cite

Within the last decade, space missions have provided a wealth of information about stellar flares. Nevertheless, what triggers these superflares, and whether they are similar to the solar counterparts, remains a great mystery. How are flares connected to active regions and what are the main causes of their occurrence? Here we investigate the activity of two K-type stars, similar in every way from mass to rotation periods and planetary systems. Even if both stars exhibited hundreds of spots, Kepler-411 produced 65 superflares, while Kepler-210 presented none. The spots of both stars were characterised using the planetary transit mapping technique which yields the intensity, temperature, and radius of starspots. The only discrepant parameter was the size of the spots. While the average radius of spots on Kepler-411 was (17 ± 7) × 103 km, for Kepler-210 the mean radius was (39 ± 18) × 103 km. That is, the star with no superflare exhibited spots twice as large as the one with 65 superflares. Thus starspot area appears not to be the main culprit of superflare triggering, but rather the magnetic complexity seems more important, as in the case of the Sun. These are important clues to the magnetic dynamo acting on these solar-type stars.

show abstract

Method for Spot-Detection on Solar-like Stars

Cited by 4 publications

References 11 publications

Superflare Ultraviolet Impact on Kepler-96 System: A Glimpse of Habitability When the Ozone Layer First Formed on Earth

Superflare Ultraviolet Impact on Kepler-96 System: A Glimpse of Habitability When the Ozone Layer First Formed on Earth

Formation, Habitability, and Detection of Extrasolar Moons

Superflares and Starspots: when size does not matter

Contact Info

Product

Resources

About