Questions tagged [exoplanet]

Questions regarding planets that lie outside the Solar System.

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1answer
39 views

Why do some pulsar planets have designations with a capital letter at the end?

The pulsar PSR B1257+12 has three planets. Most triple-planet system have designation foo b, foo c, and foo d. However, I noticed that the three planets of this pulsar (PSR B1257+12) have a ...
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1answer
125 views

Can tidally locked planets have liquid oceans on their night side, and would such a planet be habitable?

Let's say we have a tidally locked planet orbiting a star. And let's say that the conditions on its surface are just right for water to exist on its surface. Conventional wisdom says that the water on ...
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Help understanding why these two sub-Hill sphere moon stability limits are so different?

Comments under this answer to What orbital period would produce one New Moon (and one Full Moon) each year? What other effects would this produce? link to Stable satellites around extrasolar giant ...
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Radial velocity exoplanet search - can mathematical details be explained? (Bayesian periodogram MCMC)

Radial velocity (RV) is one of main methods for exoplanet search. The popular description of the method sounds simple - one should measure periodic Doppler variation of a spectral line of a star and ...
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3answers
4k views

Do celestial objects need to be big to have liquid water on their surfaces?

I mean no asteroid, planetoid that I am aware of has water on its surface. It is way more common to see ice in it. So I figured that the size of the celestial body has something to do with the cycle ...
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1answer
106 views

Is there a public record of planetary disks apart from ours?

Our planetary disk is not aligned with the rest of the galaxy. Are there publicly available records of the orientations of any other planetary disks? Especially interested in nearby stars - but I'd ...
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1answer
29 views

What exactly is a fortney grid transmission spectra modeling

I am trying to model some exoplanets and I don't understand how this model works. Below is a link of the model. What I don’t understand is how does graphing the transit depth vs wavelength provide ...
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381 views

Ramifications of black hole stellar system

Recently, I got around to seeing the movie Interstellar. In it, the characters of the movie visit a stellar system that appears to be built around a black hole instead of a star. On top of this, their ...
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Technique for folding sparse event data in order to detect an underlying periodicity?

@JamesK's answer to When will the next transit of Earth be visible from Mars? Was the last one really on May 11, 1984? lists dates of 18 transits which I've converted to days since 1500-Jan-01 as <...
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1answer
30 views

Can the Sudarsky's gas giant classification be applied to ice giants?

Based on the temperature of a gas giant around another star, I have come to understand that it is possible to guestimate its appearance; a classification scheme for gas giants developed by David ...
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2answers
45 views

Calculate mass of exoplanet from transit method

Is there any way to calculate (or at least estimate) mass of an exoplanet from transit method? I know that mass can be calculated with radial velocity method, however I would like to create program ...
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82 views

What's still needed before we can observe orbits of exomoons thereby weighing exoplanets?

Comments below this answer to How do we weigh a planet? point out that we currently cannot (or at least have not) detect moons around exoplanets, much less measure the sizes and periods of their ...
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483 views

What astronomical observations would give conclusive proof of alien life?

There are several ways we are coming closer to answering the question "is there life elsewhere in the universe?". One is by first understanding very well the origin life on our own planet. Another is ...
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236 views

What's the big deal with WD 1856+534 b?

A few days ago (september 2020) a planet candidate was announced orbiting white dwarf WD 1856+534. Some media outlets announce it as the First Possible ‘Survivor’ Planet around a white dwarf, while ...
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201 views

Have we sent radio signals to exoplanets that may be habitable?

I would like to know please whether or not we have sent radio signals to exoplanets that may be habitable. Thanks in advance !
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I have seen so many articles but how can finding exoplanet density determine composition

I have seen some articles and lectures that state but i cant seem to put my finger on on how does density affect composition and how are you able to determine composition from exoplanet density.
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1answer
29 views

Can concentration of gas in exoplanet atmosphere be found out from wavelength and absorbing radius from spectral data?

I was working on exoplanet spectral data from which I need to infer the concentration of gases. However, the exoplanet spectroscopy data contains only absorption wavelength and absorption radius. Is ...
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137 views

Trappist-1 planet albedo

Is the albedo of any of the Trappist-1 planets know? Is it high enough so if you are on the surface of one of the planets, you can see the others? I looked up the distances from the star and size of ...
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676 views

What do the words “p-type” and “s-type” mean?

As explained in various sources (such as that answer), a planet in an s-type orbit orbits one of the stars of a binary star system, whereas a planet in a p-type orbit orbits both stars. A synonym for ...
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1answer
36 views

How to recognize exoplanet transit

I am using Python package lightkurve for exoplanets searching by the transit method. When I download light curve of some star and apply periodogram, I find frequency and power of periodic components ...
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92 views

Planetary system orientation & the search for exoplanets

A quick review of photographs of galaxies will reveal that not all galaxies are orientated in the same plane as the field of view from Earth. Some galaxies are parallel to our field of view and we see ...
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Where did the idea that tidally-locked planets have a big hurricane come from?

I've been noticing a bit of a trend in the depiction of tidally-locked habitable planets, where they are shown having a huge hurricane-like storm over the daylight hemisphere. Here's an example, and ...
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1answer
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What name was voted for Tau Boötis b by the Name Exoworlds Project?

In 2015, the exoplanet Tau Boötis b was included in the Name Exoworlds Project, a project where various international astronomy organizations would propose names for a selection of known exoplanets ...
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How Can I interpret this particular light curve without reading data on the side

There is only one dip in flux recorded. How can I interpret this particular light curve and find planetary radius https://exo.mast.stsci.edu/exomast_planet.html?planet=55Cnce
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45 views

How can I find the radius of a exoplanet using doppler spectroscopy [closed]

I have the stellar and planet mass, planet velocity, radial velocity of star, stellar semimajor axis. How should I go about to find the radius of this exoplanet?
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290 views

What does BJD-2450000 mean?

In different papers I've encountered time indications in BJD-2450000. I know that BJD stands for Barycentric Julian Date, but I don't understand the meaning of the suffix -2450000. This is an example ...
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1answer
87 views

Are there ways to determine a star's spectral type without the spectrum itself?

Because of the lack of available data online, I am trying to find other ways to determine an exoplanet's host star's spectral type.
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51 views

Does anyone have spectra on exoplanet HD 219134b? How could one know either way?

I have foraged through the internet to no avail. Is there a way to systematically check if spectra from a given exoplanet has been reported, like a catalog or list of references, or is a literature ...
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1answer
169 views

Fractional contribution of secondary star

What do we mean by "the luminosity fraction" and "the fractional contribution of the secondary star" of binary stars? can anyone suggest any method to calculate them theoretically?...
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1answer
28 views

When graphing radial velocity measurements, whats the relationship between days and the orbital phase

I graphed the radial velocity measurements for various planets, however, I am able to calculate the RV and the phase but whats the translation between phase and days. I want it to be days vs RV.
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When was the concept of rogue planets first theorized?

So after watching the Kurzgesagt video about life on rogue planets I became fascinated by the concept. I did some digging, and the earliest reference to the concept I could find was Philip Wylie's ...
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2answers
109 views

How to understand exactly why gravity darkening happens on rotating stars?

Phys.org's TESS delivers new insights into an ultrahot world links to KELT-9 b's Asymmetric TESS Transit Caused by Rapid Stellar Rotation and Spin–Orbit Misalignment (readable in arXiv) The assymetric ...
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Can exoplanets be found using neutrino detectors?

I read that KamLAND can detect geoneutrinos produced by thorium and uranium decay in Earth's crust. Could a larger detector detect neutrinos from other planets in the solar system or perhaps even ...
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5answers
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Why are there no terrestrial planets with a subsurface ocean?

Subsurface oceans in satellites are pretty common: Europa, Enceladus, Ganymede, Callisto, maybe Pluto... This is due to tidal heating of their host planet, Jupiter and Saturn, which heats up the inner ...
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How to project an arbitrary elliptical orbit onto the night sky plane?

An ellipse E is arbitrarily oriented in 3-D space with the origin at one of its foci. Use the standard elements provided in the figure. Assume the reference direction $\gamma$ or $\gamma'$ is the ...
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1answer
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Why is there no Proxima 'a' planet? I'm confused about the naming convention [duplicate]

Why is there no exoplanet around Proxima Centauri designated with the letter 'a'? There is, famously, a 'b' and now a newly confirmed 'c'.... I have read that exoplanets around a star are designated ...
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1answer
112 views

Are there other planetary systems where gas giants are on the inside to rocky planet orbits?

I understand that formation theories for gas giants suggest they should be born further away where there is more gas for them to monopolize vs the sun, and then to form Hot Jupiters they need to ...
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1answer
69 views

Stellar age determination - code

I'm trying to determine the age of some stars. I have many parameters that characterize these stars: $T_{eff}$ ,log ${g}$ ,$[Fe/H]$, $V$... I've tried to use the isochrones package but so far no ...
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2answers
187 views

Get orbital period of exoplanet from light curve using astropy.timeseries

I am using astropy and I would like to calculate orbital period of an exoplanet by its star's light curve. I follow tutorial in astropy docs and I use data from Kepler in Nasa Exoplanet Archive. ...
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1answer
62 views

Pair together light curve and radial velocity data of specified star

I would like to create a web application that works with light curves and radial velocities of stars with exoplanets. I found a NASA bulk data download with both light curves and radial velocities (it'...
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1answer
83 views

How many times can iron be detected for the first time in an exoplanetary atmosphere?

I see today that there's a story about the first detection of iron in an exoplanetary atmosphere, in this case in the atmosphere of the ultra-hot Jupiter KELT-9b. I remember there being a story a ...
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1answer
160 views

Is it possible that some of the confirmed exoplanets are in fact primordial black holes?

Recently astronomers discovered a black hole lying just 1000 light-years from Earth, in a triple star system (HR 6819) that can be seen with the naked eye. This discovery has increased the possibility ...
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Has the Kepler data been examined for light curves due to phase changes of non-transitting hot Jupiters and other?

I found this article http://www.epj-conferences.org/articles/epjconf/pdf/2011/01/epjconf_ohp2010_03005.pdf from 2011 announcing that two dozen secondary eclipses of "hot Jupters" have been seen in ...
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1answer
420 views

Are all models of ocean planets theoretically cloud covered?

Take for example an ocean planet slightly smaller than the Earth. Let's say it has a planet-wide ocean that is on the average 10 miles deep. Say for argument sake, that there is a molten, rotating ...
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1answer
183 views

How frequently do Jupiter & Regulus have triple conjunctions?

I am wanting to know if the triple conjunction of Jupiter with Regulus in: Sep 10, 3 BC Feb 7, 3 BC & May 8, 2 BC with Jupiter later having a conjunction with Venus in Jun 17, 2 BC has happened ...
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Radial velocity data in ALADIN or TOPCAT for Binary Systems

I just installed both, Aladin and Topcat VO tools. I want to know how to search for: HD 226868 and A0620-00 radial velocity data or photometric curves to derive the hidden black hole mass in those ...
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1answer
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Why does the number of extrasolar planets vary in different sources?

There are at least three catalogues that are counting up-to-date discovered exoplanets. What criteria do they use to count the number of planets? Every catalogue has a different count value. So at ...
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How actively is Deep Learning being used in exoplanet identification?

Papers, like this one from Google, show that Deep Learning and Machine Learning are effective in detecting exoplanets from luminosity data provided by telescopes like TESS or Kepler. These models ...
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4answers
365 views

Why are there no photos of exoplanets?

There are a lot of photos of diffrent astronomial objects such as galaxies, nebulae and stars of which some are very far away. However there are no real photos of exoplanets (by “real photos” I mean ...
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Is Jupiter still an anomaly?

I remember a few years ago hearing that Jupiter was an anomaly in the landscape of exoplanets. Back then, most Jupiter-mass planets discovered were Hot Jupiters, orbiting very close to their host star....

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