Planets around OY Carinae and HU Aquarii?

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Planets around OY Carinae and HU Aquarii?

Post by Edasich on 23rd November 2009, 8:58 am

Now, superplanet around the well-studied 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.

But...

The modulation couldbe due to the presence in the system of a third object - an M 0.007M⊙ brown dwarf or massive planet with orbitalradius a  9.7 AUs but this is very unlikely since most wellobserved CVs show cyclical period changes (Baptista et al.2003 and references therein).

I hope not.

And then 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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Planet at OY Carinae?

Post by Edasich on 8th July 2014, 11:17 am

Long time ago I discussed of this system in Unconfirmed Planets section. It seems confirmed.

An orbital period analysis of the dwarf novae OY Carinae

By using our twelve new CCD times of light minimum of OY Carinae (OY Car) together with those collected from the literature, it is found that the O-C curve of OY Car shows a downward parabola with an amplitude of 27.8 s and a cyclic change of a period 14.0 yr. The period decrease is opposite to the hypothesis of mass transfer, and it cannot be explained by angular momentum loss via gravitational radiation. The Rappaport et al. (1983)'s magnetic braking (MB) prescription is adopted to explain the observed orbital period decrease. The cyclic change of period is analyzed with the light travel-time effect that originates from gravitational influence of a third body. The mass of the third star is determined to be M3sini‧=0.008097(0.000014) M⊙=8.48(0.02) MJup, suggesting that it may be a critical substellar object between brown dwarf and giant planet. If the orbital inclination of the third body equals 90, the distance between the third body and the mass centre of the whole system is about 6.18(0.45) AU.
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Re: Planets around OY Carinae and HU Aquarii?

Post by Lazarus on 8th July 2014, 2:51 pm

Publication date 01/2015? Where's my FTL drive?

Interesting but IMHO there are still various issues with planets around post-MS binaries that need to be addressed before these systems can be considered convincing.
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Re: Planets around OY Carinae and HU Aquarii?

Post by Sirius_Alpha on 8th July 2014, 5:31 pm

Lazarus wrote:Publication date 01/2015? Where's my FTL drive?
Download the paper, submit it and call it scooped Laughing

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Re: Planets around OY Carinae and HU Aquarii?

Post by Edasich on 9th July 2014, 12:14 pm

Anyway it's been listed in EPE:

http://exoplanet.eu/catalog/oy_car_b/
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Re: Planets around OY Carinae and HU Aquarii?

Post by Stalker on 10th July 2014, 4:27 am

I cant find my source but I have noted that OY Carinae's secondary is an "EF Eridani B" like object candidate with 68 MJ.

EDIT:Yep

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