Unconfirmed/Unpublished Planets Catalogue

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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Sirius_Alpha on 4th July 2009, 2:30 pm

Near-Infrared Variability in the 2MASS Calibration Fields: A Search for Planetary Transit Candidates
http://www.iop.org/EJ/abstract/0067-0049/175/1/191/

ABSTRACT. The Two Micron All Sky Survey (2MASS) photometric calibration observations cover ~6 square degrees on the sky in 35 "calibration fields", each sampled in nominal photometric conditions between 562 and 3692 times during the 4 years of the 2MASS mission. We compile a catalog of variables from the calibration observations to search for M dwarfs transited by extrasolar planets. We present our methods for measuring periodic and nonperiodic flux variability. From 7554 sources with apparent Ks magnitudes between 5.6 and 16.1, we identify 247 variables, including extragalactic variables and 23 periodic variables. We have discovered three M dwarf eclipsing systems, including two candidates for transiting extrasolar planets.

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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Lazarus on 4th July 2009, 2:50 pm

Free-access full version of above available on arXiv at http://arxiv.org/abs/0709.1182
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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Edasich on 4th July 2009, 3:28 pm

Thanks to notify this article, SiriusAlpha Wink

UPDATE

A pair of brown dwarfs in tight orbit around two bright binary Am stars in eccentric orbit? affraid

As far as I've read, it seems so:

INCREASED MULTIPLICITY OF 77 CYGNI, V815 HERCULIS AND HD 140122

For companions of HD 140122 A and B minimum masses of 0.03-0.02 Mso are given (i.e 30-20 Jupiter masses).
Orbital Periods 10.87 and 15.77 days and eccentricities 0f 0.1 and 0.29 respectively.

Sounds incredibile, doesn't it? Considering bright stars (masses 3.3 and 2.1 Solar Masses) have an orbital period of 54 years (around 25 AUs) and a high eccentricity (e=0.72). alien


Last edited by Edasich on 5th July 2009, 6:26 am; edited 1 time in total (Reason for editing : Added new unconfirmed objects)
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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Edasich on 18th July 2009, 8:15 am

A Putative brown dwarf in tight orbit around young star AA Tauri

Title: Eclipses by circumstellar material in the T Tauri star AA Tau. II. Evidence for non-stationary magnetospheric accretion

We report the results of a synoptic study of the photometric and spectroscopic variability of the classical T Tauri star AA Tau on timescales ranging from a few hours to several weeks. Emission lines show both infall and outflow signatures and are well reproduced by magnetospheric accretion models with moderate mass accretion rates and high inclinations. The veiling shows variations that indicate the presence of 2 rotationally modulated hot spots corresponding to the two magnetosphere poles. It correlates well with the HeI line flux, with B-V and the V excess flux. We have indications of a time delay between the main emission lines and veiling, the lines formed farther away preceding the veiling changes. The time delay we measure is consistent with accreted material propagating downwards the accretion columns at free fall velocity from a distance of about 8 Rstar. We also report periodic radial velocity variations of the photospheric spectrum which might point to the existence of a 0.02 Msun object orbiting the star at a distance of 0.08 AU. During a few days, the variability of the system was strongly reduced and the line fluxes and veiling severely depressed. We argue that this episode of quiescence corresponds to the temporary disruption of the magnetic configuration at the disk inner edge. The radial velocity variations of inflow and outflow diagnostics in the Halpha profile yield further evidence for large scale variations of the magnetic configuration on a timescale of a month. These results may provide the first clear evidence for large scale instabilities developping in T Tauri magnetospheres as the magnetic field lines are twisted by differential rotation between the star and the inner disk.

Emphasis mine.
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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Edasich on 24th July 2009, 5:55 am

Brown dwarf around 44 Bootis?

Patterns in the Long Term Behavior of Eclipsing Binary Star System 44i-Bootis

Previously, we have assembled data on the binary star system 44i Bootis, collected by our group and others over nearly a century, concerning the timing of its primary eclipses. These have been previously modeled by an ephemeris equation, assuming a constant orbital period. We have previously shown that the system is slowing down a uniform rate. We present data demonstrating a small sinusoidal trend in the remaining differences between eclipse time observations and calculations (an O-C diagram). We sought to model the cause of this variation by the gravitational interaction of a planet orbiting the binary star pair. Such a planet would necessarily be a brown dwarf of 0.0475 solar masses, with a semi-major axis of 10.729 AU. We are examining the stability of such an orbit. We also present initial data for the binary star system VW Cephei.
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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Lazarus on 24th July 2009, 6:57 am

W UMa systems are notably prone to period changes, which may well be intrinsic and due to matter transfer between the two stars. Obviously have to wait for a more detailed paper, but I'm quite sceptical of this claim.
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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Sirius_Alpha on 24th July 2009, 10:45 am

I find it interesting, "such a planet would ... be a brown dwarf".
Maybe that's it. Maybe there is no need to distinguish between the two.

Ahh... I don't want that headache again.

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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Edasich on 28th July 2009, 9:41 am

A neglected brown dwarf candidate around bright star?

CHAOS: The Cornell High-Order Adaptive Optics Survey for Brown Dwarfs

The Cornell High-order Adaptive Optics Survey for brown dwarfs (CHAOS), currently about 90% complete, uses the Palomar Hale Telescope's adaptive optics system to survey 80 bright stars out to 13 parsecs. Using the telescope's AO Science camera, brown dwarf companions 4-200 AU can be identified using coronagraphic imaging and spectroscopic modes. We will be using monte carlo simulations to create population models consistent with the CHAOS data set.Currently, we have observed 70 systems out of a target sample of 80. Five candidate companions await follow-up observations. As of now, no systems in the target sample have shown strong evidence of having brown dwarf companions. These early results support previous speculations of a ``brown dwarf desert'' at orbital separations out to 200 AU.While the target sources revealed no evidence of brown dwarf companions, accompanying observations of calibration stars provided evidence of an early methane dwarf candidate around the binary system HD150451AB. Forty seven parsecs from earth, the candidate indicated a projected orbital separation of 280 AU.

And it would be confirmed too, since it was firstly claimed in 2002:

A T-dwarf Companion to HD150451AB

We present strong evidence of an early-type methane brown dwarf companion to the binary system HD150451AB. We obtained J-band and K-band diffraction-limited images with the Palomar Adaptive Optics system (PALAO) and the PHARO camera on the Hale 5-meter telescope, revealing an object having infrared colors and luminosities consistent with an early-type T-dwarf. We also obtained high-resolution astrometry over two years, showing common proper motion and confirming the object as a true physical companion. We used differential methane band imaging with the Palomar Wide-field Infrared Camera (WIRC) to reveal methane absorption, confirming the T-dwarf nature of the object. We observed apparent variability in the methane depression with ~{50%} amplitude over a ~{72}-hour timescale. After Gliese 229B and Gliese 570D, HD150451C is only the third known methane binary companion to a normal star.
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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Edasich on 1st August 2009, 9:57 am

Another tantalizing announcement.

BD+20 1790 b: Chronicle of an exoplanetary discovery


In this contribution we report evidence for a planetary companion around a young and active late-type K star. Our group has been developing a study of stellar activity and kinematics for this star over the past years. Previous results show a high level of stellar activity, with the presence of prominence-like structures, spots on surface and strong flare events. Radial velocity (RV) variations with a semi-amplitude of up to 1 km s-1 were detected. When the nature of these variations were investigated it was found that they are not due to stellar activity. Based upon the analysis of bisector velocity span, as well as Ca II H & K emission, we report that the best explanation for RV variation is the presence of a sub-stellar companion. The Keplerian fit of the RV data yields an orbital solution for a close-in massive planet with an orbital period of 7.783 days. Also, the presence of this close-in massive planet chould be an interpretation for the high level of stellar activity detected.

But no mention of this exoplanet in the web Sad

But the wait is (almost) over

http://exoplanet.eu/star.php?st=BD%2B20+1790

Though 57 Gyrs.... no,no,no Mad
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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Edasich on 11th August 2009, 7:42 am

Never released this one.

A Planet Orbiting the F-star 30 Ari B

Up to now our knowledge on frequency of planets of stars that are more massive than the sun is rather limited. In here we present the discovery of a planet orbiting the F4V-F6V star 30 Ari B, which is also a member of a hierarchical triple-star system.

And I quite don't wanna pay ASPBooks to view a little PDF! Mad

*Neither I could*


EDIT

Confirmed. Listed at EPE:

http://exoplanet.eu/star.php?st=30+Ari+B


Last edited by Edasich on 10th December 2009, 5:07 am; edited 1 time in total
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Re: Unconfirmed/Unpublished Planets Catalogue

Post by marasama on 11th August 2009, 3:45 pm

LP 944-20 / BRI B0337-3535 (field BD)
A = (brown dwarf)
b = ? = if Porb<2yrs then Mass≤13Mj
- RV variations is either due to surface features (that does not resemble a dark sunspot)
or a companion.
Eike W. Guenther & Guenther Wuchterl, 2003
http://arxiv.org/abs/astro-ph/0302029 (page 6)

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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Edasich on 13th August 2009, 5:49 am

Thanks, Marasama, interesting paper Very Happy

Now, brown dwarf of superplanet around the well-known dwarf-nova OY Carinae?

Decrease in the orbital period of dwarf nova OY Carinae

We have measured the orbital light curve of dwarf nova OY Carinae on 8 separate occasions between 1997 September and 2005 December. The measurements were made in white light using CCD photometers on the Mt Canopus 1 m telescope. The time of eclipse in 2005 December was 168 +- 5 s earlier than that predicted by the Wood et al.(1989) ephemeris. Using the times of eclipse from our measurements and the compilation of published measurements by Pratt et al (1999) we find that the observational data are inconsistent with a constant period and indicate that the orbital period is decreasing by 5+-1 X 10^-12 s/s. This is too fast to be explained by gravitational radiation emission. It is possible that the change is cyclic with a period greater than about 80 years. This is much longer than typical magnetic activity cycles and may be due to the presence of a third object in the system. Preliminary estimates suggest that this is a brown dwarf with mass about 0.016 Msun and orbital radius >= 17 AU.

And same for Z Chamaeleontis?!

Early hints in 1994

Hubble Space Telescope observations of the dwarf Nova Z Chamaeleontis through two eruption cycles

Browsing the abstract I've found

For Z Cha the period of the reflex orbit would be greater than 25 yrs and its projected semimajor axis would be greater than 40 light seconds or 1.2x1012 cm. A third body with a mass as small as 0.01 MSun at a distance greater than 8 AUs would be enough to account for the eclipse ephemeris. Such an object would be undetectable by other means. At present there is no way to choose among these possible interpretations of the eclipse ephemeris

And the 28 yrs periodicity still confirmed in 2004;

Cyclical period changes in Z Chamaeleontis
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Re: Unconfirmed/Unpublished Planets Catalogue

Post by marasama on 1st September 2009, 4:52 pm

Possible planetary companion:
ITG 9
has picture on page 4,7
A = 0.03Ms
B = ITG 9B (ELL-YSO candidate compaions)
- ρ=4.339"=765AU, 0.010Ms, Porb=3.9x10^7d

ITG 33
has picture on page 5,8
A = 0.03Ms
B = ITG 33B (ELL-YSO candidate compaions)
- ρ=5.203"=917AU, <0.006Ms, Porb=5.3x10^7d

has picture on page 5,8
A Near-Infrared Search for Companions around Very Low Luminosity Young Stellar Objects in Taurus
http://adsabs.harvard.edu/abs/1999AJ....117.1471

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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Edasich on 3rd September 2009, 11:07 am

The presence of a tertiary companion around Z Chamaeleontis seems even more convincing:

Evidence of a Brown Dwarf in the Eclipsing Dwarf Nova Z Chamaeleonis

We presented three new CCD observations of light minima of Z Chamaeleonis. All 187 available times of light minimum including 37 photographic data are compiled, and a new orbital period analysis is made by means of the standard O – C technique. The O – C diagram of Z Chamaeleonis presents a cyclical periodic change of ~ 32.57 yr with a high significance level. We attempted to apply two plausible mechanisms (i.e., Applegate's mechanism and light travel-time effect) to explain the cyclical variations of orbital period shown in the O-C diagram. Although the previous works suggested that solar-type magnetic cycles in the red dwarf are the best explanation, the analysis of Applegate's mechanism in this paper presents a negative result. Accordingly, a light travel-time effect is proposed, and a brown dwarf as a tertiary component orbiting around dwarf nova Z Chamaeleonis is derived with a significance level of gsim81.6%, which may be a plausible explanation of the periodic variation in the systemic velocity of Z Chamaeleonis in superoutburst.
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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Edasich on 14th September 2009, 5:09 am

Not exactly about extrasolar planet, but extrasolar comets.

Do you remember the HII Region W 3(OH)? Also listed in EPE.
That region was thought to host a swarm of cometary bodies as well as a giant cometary object (Pluto-sized one, I think) at 1,000 or 10,000 AUs.

Well, here it seems it's not the only one hosting comets.

The young star BF Orionis does.

Long-Term Cyclicity of the Herbig Ae Star BF Ori: Giant Protocomets and Accretion from a Protoplanetary Disk

Having analyzed the light curve for the Herbig Ae star BF Ori, we justify the hypothesis of a giant protocomet, GPC I BF Ori, with a period of 6.3 years and semimajor axis a = 10 +/- 3 AU. Passing through periastron, such a giant protocomet partially breaks up. During each passage through periastron, the protocomet and the fragments that follow it supply dust to circumstellar space for a certain period of time. This hypothesis can account for the entire complex of observable phenomena of cyclic Algol-like activity in Herbig Ae/Be and T Tauri stars. Conditions in a protoplanetary disk after cocoon breakup are discussed. We adduce arguments for the absence of a dust disk and for the weak effect of objects other than comets on cyclic large-scale variability.
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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Edasich on 15th September 2009, 9:01 am

No paper and quite weird, since a third body with 1.3 Solar masses is already known to be located at similar orbital separation and with high eccentricity value (e=0.77).

Period analysis of the semi-detached binary V505 Sgr

The O-C curve of the Algol-type semi-detached binary V505 Sgr has been analyzed using a new method proposed by Kalimeris et al. (1994). It is shown that the orbital period oscillates with an amplitude of 0.453×10-5days and a period of aobut 41.5 years that differs from the previous period of 105 years. The physical mechanisms explaining the orbital period behaviour have been studied. It is indicated that the present period change may not be caused by the existence of the third body proposed previously. The presence of a fourth body with mass 0.013 Msun and orbit semimajor axis 17.35 AU or the magnetic activity cycle of the secondary component may be used to explain the present period change.
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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Edasich on 13th November 2009, 10:54 am

HU Aquarii. Another CV with planet? Lurking planets await in the least expected papers... *lol*

Hunting high and low: XMM monitoring of the eclipsing polar HU Aquarii

As an alternative origin the cyclic period changes could also be caused by an unseen third body in which case the variation should be strictly periodic. Taking the elementsof the quadratic plus sinusoidal ephemeris we compute the minimum mass of such a body assuming that its inclination is 90◦. The observed mass function (Borkovits & Hegedues1996) is 1.1 × 10−7M⊙ implying a minimum mass of the third body of 0.0047M⊙ (5 Jupiter masses) for an assumed total mass of the system of 1.0 M⊙. On the other hand, athird body more massive than an object at the hydrogen burning limit would require an inclination < 3◦ and istherefore not very likely.

The cyclicalvariation has a period of 6.9 yr and an semi-amplitude of∼ 9 sec.
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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Edasich on 15th November 2009, 9:25 am

It has someway something to do with unconfirmed planets since it talks about yet not discarded planetary candidate HD 203857 b.

Wikipedia page made by me with first picture uploaded:

http://en.wikipedia.org/wiki/HD_203857
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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Edasich on 13th December 2009, 12:22 pm

Back in 1970. Likely spurious or likely forgotten??

Pulsar planetary systems

However here we'd have planets around Vela and Crab Pulsar.

The former would have a 10 Mj (10-2 MSun) planet and the latter a 10-5 Msun one (0.0032 Earth masses?). Both at 0.3 AUs from their pulsars.

Here is a Ceres-mass object at PSR B1937+21.

Detecting Planets Around Pulsars


This one instead looks more recent and I need to know more about:

X-ray Timing of PSR B1509-58: A Planetary System?

We have monitored the stable pulsar B1509-58 in the 2-100 keV X-ray band with RXTE for six years, since the start of that mission in January 1996. The X-ray pulse lags the radio pulse by 0.30 +/- 0.01 in phase and there is no indication of this lag's depending on energy. We have derived a single X-ray timing ephemeris that fits the entire monitoring period, using a quintic polynomial. The timing residuals exhibit a periodic behavior with amplitude between 4 and 5 ms. This, in itself, might point to the existence of a planetary system. However, solid confirmation and an orbital period are hard to obtain because it is extremely difficult to separate the sinusoidal components from the polynomial due to the long orbital period. This pulsar is stable, but fitting its timing over long time ranges requires the higher orders in the polynomial. Those, in turn, cause features that are hard to distinguish from true sinusoids with periods of 800 to 900 days. Nevertheless, we remain confident that we will soon be able to produce reliable parameters for the first planetary system discovered through X-ray observations.


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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Sirius_Alpha on 13th December 2009, 12:27 pm

Fascinating! But, being ~7 years after that paper was published, it makes you wonder if the planetary system was disproven, or if it's turning out to be rather complex (or if everyone forgot its existence altogether ).

I want more pulsar planets. They should be easy to find if they are common. Is no one looking? Or are they just that rare?

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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Lazarus on 13th December 2009, 12:33 pm

B1509-58? Apparently it is only 1700 years old (as viewed from Earth - the pulsar is 17000 light years away), would be very surprising if there are planets there.
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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Edasich on 13th December 2009, 1:17 pm

[quote=\"Lazarus\"]B1509-58? Apparently it is only 1700 years old (as viewed from Earth - the pulsar is 17000 light years away), would be very surprising if there are planets there.[/quote]

As authors states here the age estimate could turn out doubtful

2800 Days of Monitoring the Timing of PSR B1509-58 with RXTE

But here is what I was looking for.

We have analyzed 90 observations of the young pulsar B1509-58 made by RXTE over 7.6 years.
The pulse profile can be described as a combination of two systems. The first consists of two narrow components separated by 0.14 period with an amplitude ratio of 10:3; the second consists of a single broader component. The two systems appear to be shifting with respect to each other as a function of energy.
We have derived a single timing ephemeris on the basis of the X-ray observations, using terms up to the third derivative. There is no indication that a fourth derivative is required. The resulting value of the first braking index is consistent with that derived from radio observations, but the second braking index is twice its expected value. This casts some doubt on the significance of the pulsar\'s characteristic age (1700 years).
The phase residuals have been fit with sine components, resulting in an estimate of the proper motion (45+/-25 mas/yr at a position angle of 45+/-45°) and of masses and orbital radii (ranging from 0.7 to 2 AU and 0.25 to 2.5 earth masses) of planetary material - if that is the cause of these phase excursions.


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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Lazarus on 13th December 2009, 1:27 pm

Taking a look at the citations of that paper, I find this one about 21 years of timing of B1509-58, which conveniently enough is on the arXiv.

Another possible cause of apparent timing noise in some objects is the presence of one or more planet-mass objects orbiting the neutron star. If these planets are of sufficiently low mass, their presence may appear to be ‘timing noise’ for many years. In fact, this possibility has been suggested by Rots (2002, 2004) for PSR B1509−58. He performed a fit consisting of five orbits of ∼solar mass planets to the same RXTE timing residuals that we have used in our analysis. To determine if these orbits were stable, we performed a periodogram analysis on both the X-ray timing residuals and the entire data set. We found roughly similar periodicities in the 7.6-yr X-ray data set, but these periodicities are not seen in the entire 21.3-yr data set. This indicates that the ‘periodicities’ are not stable in time and thus likely do not represent orbits of planets around PSR B1509−58.
(emphasis mine)

I'm guessing that by "~solar mass planets" it is meant "planets with comparable masses to those in our solar system"...
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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Edasich on 13th December 2009, 1:29 pm

And today a plenty of forgotten pulsar planet candidates

Searches for pulsar planetary systems

Earth-mass planets at PSR B1911-04 and PSR B1929+10. Periods 7 and 12 years respectively.
Assuming a 1.4 Msun pulsar, semimajor axis should be around 4.09 and 5.8 AUs.
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Re: Unconfirmed/Unpublished Planets Catalogue

Post by Lazarus on 14th December 2009, 6:30 pm

Sirius_Alpha wrote:I want more pulsar planets. They should be easy to find if they are common. Is no one looking? Or are they just that rare?
Maybe there are some in the pipeline... not saying any more though... Smile
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Re: Unconfirmed/Unpublished Planets Catalogue

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