Unconfirmed/Unpublished Planets Catalogue

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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Lazarus on 20th September 2008, 1:10 pm

marasama wrote:Man, I cannot find this puppy in SIMBAD.
While WD 1847-223J is unrecognised, there is an object WD J1847-223... might be that one.
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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Lazarus on 24th September 2008, 1:55 pm

Deep MMT Transit Survey of the Open Cluster M37 IV: Limit on the Fraction of Stars With Planets as Small as 0.3 RJ

Unfortunately, no planet transits were detected around stars in the M37 cluster, but an unrelated field star shows signs that it may have a Jupiter-radius planet in a 0.77 day orbit (an "extremely hot Jupiter" or to use the term that the SWEEPS survey used for planets in this period range, an ultra-short-period-planet). Because the star is faint, getting an RV confirmation will be tricky.
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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Sirius_Alpha on 1st October 2008, 8:42 pm

m sini i < 0.5 M_jup planet with P ~ 5 days from HARPS.
http://arxiv.org/abs/0810.0201

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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Edasich on 19th November 2008, 8:55 am

An unconfirmed recent microlensing event:

OGLE-2002-BLG-045 cat

Assuming host star's mass around 0.3 MSun a planet of a few Jupiter masses is likely to orbit this faraway star.
No orbital parameters available though pale .

The case is still under study.

Source paper:

Repeating microlensing events in the OGLE data
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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Edasich on 19th November 2008, 10:52 am

Vega was supposed to host a <30 Mj within 30 AUs or so. Solstation talks about http://www.solstation.com/stars/vega.htm

Modelling simulations by Wilner's team (including www.harvard.edu/hco/astro/people/homepages/holman.html" target="_blank" rel="nofollow">Matt Holman, www.harvard.edu/hco/astro/people/homepages/ho.html" target="_blank" rel="nofollow">Paul Ho, and Marc Kuchner) suggested that the semimajor axis of the planet's orbit may center around 30 AUs -- at Neptune's orbital distance in the Solar System. The simulations also indicated that the planet must be smaller than 30 times Jupiter's mass. A larger planetary mass would cause the observed dust clumps to overlap by destroying and the hypothesized orbital resonances

Then the Neptune-like planet model upcame and the "Vegan dwarf" were not discussed anymore.

Other simulations by Nick N. Gorkavyi and Tanya A. Taidakova (Schafer Corporation) of an observed dust disk ring arc at 95 AUs also suggested that there may be a sub-Jovian planet between 90 to 100 AUs out from Vega. The simulations indicated that one (or more) very massive planet within 50 to 60 AUs may have destroyed the inner circumstellar dust disk by gravitational scattering (Abstract for 2002 AAS session 86.07).

There is also an animation (Vega b looks quite eccentric too; e=0.6):




Assuming the planet laying at 30 AUs and e=0.6, we should have an object swinging between 12 AUs and 48 AUs (apastron). Moreover if the habitable zone lies at 7 AUs, such object would lay in system's water zone at periastron and beyond the snowline at apastron.

More informations about simulations here: The Geometry of Resonant Signatures in Debris Disks with Planets

Maybe the methods and instruments which have allowed the detection of Fomalhaut b and HR 8799's trio could unveil exoplanets also around this bright star. cyclops
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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Edasich on 19th November 2008, 11:27 am

- GM Aurigae: 1.7 Mj, 2.5 AUs - no more articles related

Sure? From Cavities in inner disks: the GM Aurigae case.



Context: Recent modeling based on unresolved infrared observations of the spectral energy distribution (SED) of GM Aurigae suggests that the inner disk of this single TTauri star is truncated at an inner radius of 25 AU. Aims: We attempt to find evidence of this inner hole in the gas distribution, using spectroscopy with high angular resolution. Methods: Using the IRAM array, we obtained high angular resolution ( 1.5) observations with a high S/N per channel of the 13CO J=2{-}1 and C18O J=2{-}1 and of the 13CO J=1{-}0 lines. A standard parametric disk model is used to fit the line data in the Fourier-plane and to derive the CO disk properties. Our measurement is based on a detailed analysis of the spectroscopic profile from the CO disk rotating in Keplerian velocity. The millimeter continuum, tracing the dust, is also analyzed. Results: We detect an inner cavity of radius 19 4 AU at the 4.5σ level. The hole manifests itself by a lack of emission beyond the (projected) Keplerian speed at the inner radius. We also constrain the temperature gradient in the disk. Conclusions: Our data reveal the existence of an inner hole in GM Aur gas disk. Its origin remains unclear, but can be linked to planet formation or to a low mass stellar companion orbiting close to the central star ( 5-15 AU). The frequent finding of inner cavities suggests that either binarity is the most common scenario of star formation in Taurus or that giant planet formation starts early

Probably the cavities observed in GM Aur's disk may be produced by two planets. A 5 Mj object at 8.5 AUs and a 5-10 Mj (probably 7 Mj) within 15 AUs.
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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Edasich on 22nd November 2008, 6:25 am

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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Edasich on 6th December 2008, 9:29 am

Sirius_Alpha wrote:According to SIMBAD, TYC 7190-2111-1 (TWA 7) may have a planet.

Retracted. Background object.

Reference for Pi Herculis

Long-period, low-amplitude radial velocity variations in the K giant star pi Herculis: rotation, substellar companion or non-radial pulsations?
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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Edasich on 8th December 2008, 8:16 am

1 - Possible third body around YY Geminorum eclipsing binary:

YY Geminorum: A Very Late Type Close Binary with Possible Magnetic Stellar Wind

Such object would have between 55-60 times the mass of Jupiter and located within 8-10 AUs.

2 - 21 Herculis system is triple with a circumbinary brown dwarf at 0.44 AUs with mass between 35-40 Jupiter masses.

The spectroscopic binaries 21 Her and gamma Gem
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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Edasich on 11th January 2009, 6:05 am

The Radial Velocity Variability of the K Giant beta Ophiuchi. II. Long-Period Variations

Possible presence of a 1-3 Jupiter masses planet in 143 days orbit (a= 0.57 AUs, assuming stellar mass of 1.2 MSun).

Another periodicity of 295 days was detected in the K giant Delta Sagittarii for which a 2 Mj object (am I right?) was suspected in 1995. No paper available anywhere. Here I'm quoting Intriguing, Low-amplitude Periodicity in the Radial Velocities of Delta Sagittarii:

We present the initial results of the analysis of the precise radial velocities of the relatively little-studied star delta Sagittarii, K2.5 IIIa, HR 6859. The data were obtained at the Canada-France-Hawaii Telescope using the hydrogen fluoride absorption cell technique. The periodogram shows significant peaks at 2.8 days (K=104 m s(-1) ), 63 days (K=85 m s(-1) ), and 295 days (K=72 m s(-1) ). Because of our limited data the true period cannot be distinguished from these possibilities due to aliasing. This giant is an interesting example of a star having a radial velocity periodicity which may be attributed to intrinsic variability, rotational modulation, or the presence of a low M_2 sin i companion (see A. Walker et al., this conference). More observations are urgently required to determine the true period and to discover the underlying origin for this star's radial velocity variability.

As we're talking about K giants, does anybody have a reference about the couple of brown dwarfs orbiting the bright K giant Iota Aurigae? Those were mentioned in a conference, I guess, has there been any update or paper about?
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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Lazarus on 11th January 2009, 9:57 am

Regarding the iota Aurigae results, the conference abstract is here. While there hasn't yet been a paper specifically about the system, this paper discussing radial velocities of K giants lists a period of 1586 days for the star.
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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Edasich on 11th January 2009, 1:49 pm

Thank you, Lazarus Wink
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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Lazarus on 12th January 2009, 3:27 pm

Actually I only partially read the table - two periods are listed for the star: 767 days and 1586 days.

The catalogue given in paper III in the series lists log g = 1.15. The CHARM2 data give a weighted average angular diameter (for a uniform disc) of 7.03 mas, and the new Hipparcos parallax of 6.61 mas.

Using these values, I obtain a mass of the star 6.7 solar masses (this assumes that the radius and the gravity determination are measuring the same bit of the star of course). The distances of the two companions from the star would then be 3 AU and 5 AU. For comparison, the stellar radius is 0.53 AU. The planets will therefore be extremely hot!
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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Edasich on 13th January 2009, 2:58 pm

Somewhat a HD 3346-kin. If that giant were actually a brown dwarf host.
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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Lazarus on 31st January 2009, 7:41 am

Regarding the paper in which the periodicities are listed, among other things it also suggests a second object around HD 59686 = HIP 36616 with a period of 3507 days.

(note that the planets around 91 Aqr and HD 59686 have not had their discoveries published yet, the discovery reference is a conference abstract, and these systems are not listed in the Catalog of Nearby Exoplanets)
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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Edasich on 11th April 2009, 9:17 am

I was browsing old papers and I've found some interesting abstract, though old *and likely obsolete*. I thought it were worth notifying by the way.

1) Fulbright et al. (1993) - JHK photometry of WD 0950+139

Apart from the curious name of the author *LOL*, there is a possible evidence that secondary component of a hot white dwarf may be a Jupiter-mass (and sized) Jovian planet rather an usual M-dwarf. Orbital period spanning between 0.5-5 days. If true, this object would be 550 K hot.

2) Marsh et al. (1993) - Do the spectral energy distributions of GK Tauri and HK Tauri indicate the presence of planetary companions?

Possible presence of massive jovians around these two young stars. To be confirmed since long time...
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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Edasich on 15th April 2009, 8:27 am

1) Amongst possible explanations for Wolf 359's flare activity, a planetary companion may not be ruled out at all. Such an object would yield 20% of Jupiter's mass (0.2 Mj) and be located at 0.015 AUs from host star. If true, that would be the closest "Hot Jupiter" to our Sun.

Details here:

Activity-induced radial velocity jitter in a flaring M dwarf

2) Possible planetary companion around evolved subgiant HR 1362 (=EK Eridani, HD 27536) (LEK Eri=13.6 LSun MEK Eri=1.85 MSun). It would host a 3.9 Mj planet in 306.9 days orbit (1.2 AUs) and eccentric orbit (e=0.5).

Paper:

Binarity, activity and metallicity among late-type stars I. Methodology and application to HD 27536 and HD 216803
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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Sirius_Alpha on 18th April 2009, 9:22 pm

From
Extrasolar planet population synthesis II: Statistical comparison with observation
http://arxiv.org/abs/0904.2542

... We note that Cumming et al. (2008, their fig. 5) have shown that in the Keck Planet search program a group of very massive candidates (M sin i >~ 20 M_J) at periods >~ 2000 d (a >~ 3 AU) exists which have not yet been announced.
...

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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Edasich on 5th May 2009, 12:26 pm

1) - An unresolved low mass object is still thought to orbit a young star in IC 348 Open Cluster (i.e Omicron Persei's one). Possible 6 Mj protoplanet located at 3.3 AUs from the star.

The unusual pre-main-sequence star V718 Per (HMW 15)

Maybe spot activity, maybe not.

2) - I've found an abstract about such a WASP-17 in ADS service:

WASP-17 - testing the paradigm of pM/pL class planets

The structure, formation and fate of hot Jupiter exoplanets is governed by the properties of their atmospheres. There is an urgent need for for strong observational constraints to guide the development of model atmospheres for hot Jupiters. WASP-17b is a newly discovered transiting hot Jupiter exoplanet. It has the lowest density of any transiting hot Jupiter discovered to-date. The host star, WASP-17, is a bright (VD11.6) F6V star. This combination of factors make WASP-17 a key object for testing the current paradigm in which hot pM class planets have stratospheres and cooler pL class planets do not. We will use Spitzer to observe the secondary eclipse of the planet by its host star at 3.6um and 4.5um, and use these data to measure the brightness temperature at these wavelenghs. In the current paradigm, this pM class planet should show evidence of a stratosphere from the ratio of the brightness temperatures at these wavelengths. We will also use transmission spectroscopy to determine independently whether WASP-17b has a stratoshere. VLT time to obtain the required spectroscopy has already been approved. WASP-17 is currently the only pM class planet apart from HD209458 for which the results from the two methods can be compared. The Spitzer data that we will obtain for WASP-17 are essential for us to fully understand exploit the Spitzer observations of exoplanets that will be obtained in the warm mission.

And hints for WASP-18 and WASP-19 (and 16?). No full paper for both.

Lightcurves of two newly discovered ultra-short period planets

The structure, formation and fate of hot Jupiter exoplanets is governed by the properties of their atmospheres. There is an urgent need for for strong observational constraints to guide the development of model atmospheres for hot Jupiters. One of the most powerful techniques for probing hot Jupiter atmospheres is to observe the small variation in infrared flux through the orbital cycle for transiting hot Jupiters. These observations can be converted into a map of the temperature distribution around the planet. This gives us a direct measurement of the way heat is redistributed through the planet's atmosphere. The processes that redistribute heat from the day-side to the night-side in these tidally locked planets are very poorly understood. This limits our ability to interpret observations of hot Jupiters obtained with Spitzer and other instruments. Phase variations are small so they have only been succesfully observed in a handful of hot Jupiter systems. There are, as yet, no detections of the phase variation in any transiting hot-Jupiters with atmospheres hot enough to have a stratosphere, and only one (HD189733) for a cooler transiting hot Jupiter. We will observe the lightcurves of WASP-18 and WASP-19, to newly discovered ultra-short period planets (P<1day). These are key objects for understanding heat redistribution in hot Jupiters because the irradiation of their day-side is so extreme.
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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Edasich on 9th June 2009, 10:53 am

A trio of neglected solar-like stars with brown dwarf companions:

ELODIE low-mass companions to solar-type stars

Except HD 174457 which seems hosting just a low-mass star rather a brown dwarf.
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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Edasich on 21st June 2009, 10:35 am

Browsing SIMBAD I've noticed that star TYC 2534-698-1 could host a SuperWASP planetary candidate listed in EPE amongst unconfirmed/controversial planets.
Note that TYC 2534-698-1 is already known to host a brown dwarf companion in close and eccentric orbit.

If both confirmed, it would turn out an interesting hot jupiter+brown dwarf system.

P.S

I've tried a simulation with Systemic Console using RV sets available. Surely additional data are required to confirm both or one of two objects, but a preliminary solution (with relatively low Chi and zero jitter) gives me a more eccentric orbit for brown dwarf (e=0.65) and a smaller orbital period for the hot jupiter (1.89 days rather 2.67 days). Hot planet's mass around 6 times that of Jupiter.
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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Lazarus on 21st June 2009, 10:43 am

The discovery paper for the brown dwarf states the RVs are incompatible with the SuperWASP candidate. I guess the SuperWASP planet goes into "disproven"...
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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Sirius_Alpha on 27th June 2009, 12:43 pm

Something going on at HD 84117?
From:
The Frequency of Low-mass Exoplanets
http://arxiv.org/abs/0906.4619

There is at least one case (HD 84117) where the observed velocity variability distribution appears to deviate significantly from a Gaussian distribution ... show no evidence for significant variability over the course of the 48n run, though no obvious periodocity, nor with an obviously Keplarian shape. (No other star observed on this run shows a similar variability trend, indicating that the variability seen is not a systematic effect of our measurement system. Adding additional AAPS data of similar quality taken in 2005 indicates that HD 84117 has shown excess velocity variability since 2005 over that expected from activity jitter alone (with an RMS of 4.7 m/s). The periodogram of HD 84117 shows essentially no power at periods of less than 40 d, though a complex, broad power distribution is seen at longer periods, i.e. longer than the time-span of the observations. We can therefore fit the data with no compelling single Keplarian. HD 84117 may either contain multiple planets, which will require intensive observation to disentangle, or may be a star with an unusual class of velocity variability. We can nonetheless say with confidence that it does not host a low-mass exoplanet in an orbit of less than ~30 d.

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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Lazarus on 27th June 2009, 1:46 pm

From that same paper, this time regarding HD 4308, which already is known to host a hot Neptune...
Finally, we note that the residuals to the Rocky Planet Search data alone (Fig. 4) are suggestive of a further periodicity in that data set at 30-40 d. To examine the possibility of there being a second planet present in this data, we have constructed the 2DKLS for the AAT and HARPS velocities with the Keplerian of Fig. 6 removed (see Fig. 7). The result is suggestive of power at period between 30-80 d. While potential planets at 32 d and 48 d periods can be fitted to this data, they do not do so with a significance that warrants a claim to have detected further planets in this system.
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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Sirius_Alpha on 27th June 2009, 2:09 pm

The graph of the residuals they showed does have a nice curve to it. But I can see how it's might not be statistically significant.

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Re: Unconfirmed/Unpublished Planets Catalogue

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