Celestia Forums

Well ill certainly try that hungry, tnx.

zhar2 wrote:Well ill certainly try that hungry, tnx.

Any time! I wish you the best of luck!

Here's a .ssc for the planet of Beta Pictoris, assuming that it is located in an edge-on orbit with semimajor axis 12 AU, eccentricity 0.1 (as determined from modelling perturbations in the dust disc - see Freistetter et al. 2008, A&A 466, 389) with the periastron pointing SW (towards the less extended side of the circumstellar disc). The orbit is set up to reproduce the possible detection of the planet at position angle 31.8 degrees and projected separation 8 AU on 2003-11-13, as described in Lagrange et al. 2008, accepted in A&A.

Haven't been able to find out the sense of the rotation of the Beta Pictoris disc (is the NE or SW extension moving towards us?). The mean anomaly is chosen so that the planet is currently (in 2008) located close to the star, which is also predicted if the semimajor axis is 8 AU.

I'm not putting this one in the zip file because orbital motion has not yet been detected for this planet candidate so the orbit is very preliminary.

Actually according to Oloffson, Liseau and Brandeker (2001), ApJ 563 L77 the rotation of the disc is such that the SW extension is moving towards us and the NE extension is moving away from us. Fortunately this is the same as the orbit in my above post...

There is a possibility that Beta Pictoris b was detected in transit in 1981. This would make it the earliest detection of a transiting exoplanet?

arXiv 2009: Lecavelier des Etangs and Vidal-Madjar "Is Beta Pic b the transiting planet of November 1981?"

ajtribick wrote:I've modelled Fomalhaut b by making its orbit apsidally-aligned with the dust disk, and setting up the mean anomaly to match the position angle in 2006. I've also added the possible circumplanetary disc. Because of the 400 K temperature from modelling I have rendered it as a class III planet. Parameters based on Kalas et al. (2008).

We've now got confirmation that Fomalhaut's spin axis probably aligns at right angles to the debris disc. This has prompted me to incorporate an appropriate spin axis for Fomalhaut into my big revision of nearstars.stc, as well as to add the appropriately orientated planetary orbit to extrasolar.ssc.

Grant

While we're at it, here's an update for HR 8799. This is fit III (1:2:4 resonant configuration) from Go?dziewski and Migaszewski (2009). Unstable but the timescale for disruption is longer than the age of the system. Apparently the convention for the orbital elements given there is anticlockwise from west rather than anticlockwise from north.

Emisive true

Hmm...

Fridger

At what point would a big ball of gas start to noticeably glow anyway? Estimated temperatures for these planets are 1000-1100 K for the inner two and 800-900 K for the outer one...

(Alternatively let's just say this is rendered as if we can see infrared wavelengths. Yes, I'll use that as my cop-out)

ajtribick wrote:At what point would a big ball of gas start to noticeably glow anyway? Estimated temperatures for these planets are 1000-1100 K for the inner two and 800-900 K for the outer one...

(Alternatively let's just say this is rendered as if we can see infrared wavelengths. Yes, I'll use that as my cop-out)

Did you note your typo above?

Fridger

No. Generally if I notice typos I remove them, so here is a case of me being wrong. Since I still have been unable to spot it, can you tell me so I don't make this mistake again?

(if on the other hand it is about the use of the word "point", which is clearly nonsensical and should perhaps be "approximate vague handwavey range", I'll point out that I have to put my pedant's hat in the washing machine every so often. Basic hygiene.)

ajtribick wrote:No. Generally if I notice typos I remove them, so here is a case of me being wrong. Since I still have been unable to spot it, can you tell me so I don't make this mistake again?

(if on the other hand it is about the use of the word "point", which is clearly nonsensical and should perhaps be "approximate vague handwavey range", I'll point out that I have to put my pedant's hat in the washing machine every so often. Basic hygiene.)

Andrew,

I showed the typo to you in my last but one post, but you didn't seem to notice.

Fridger

Ah because by "above" it seemed more logical to assume you were talking about the quoted text, which you had indeed placed above.

ajtribick wrote:Ah because by "above" it seemed more logical to assume you were talking about the quoted text, which you had indeed placed above.

Does this now mean in plain English that you spotted the typo?

Fridger

Having moved to Switzerland about two months ago, it appears that despite my German not improving very much, my English abilities are dropping alarmingly rapidly.

I thus conclude I am better at unlearning languages than learning them. Bummer.

I think 'e mised your point Fridger.

Chuft-Captain wrote:I think 'e mised your point Fridger.

Well, obviously, since Andrew has corrected the typo meanwhile:

Andrew wrote:Last edited by ajtribick on Tue Jun 16, 2009 0:26, edited 1 time in total.

Fridger

Sorry Andrew,

I can never resist a play on words.

(and I must admit I'm not immune to the occasional typo myslef)

CC

"myslef"