[Aavso-photometry] GJ 436 Campaign Web Page

Sat Jun 9 12:42:10 EDT 2007

Hi Aaron, hi Arne

There is a recommendation to go as blue as possible.
Do the higher scintillation and higher extinction in the
blue not more than outweigh the mentioned advantage ?
The transformation might work better in the blue, but one
will also have noisier data. IMO in general going as red
as possible (at least with higher amp exoplanets) should
be better (especially if one doesn't transform the data).

Here one can find all arXch papers on GJ 436:
<http://arxiv.org/find/grp_cs,grp_math,grp_nlin,grp_physics,grp_q-bio,grp_stat/1/all:+AND+436+GJ/0/1/0/all/0/1>
and referencing GJ 436 b:
<http://arxiv.org/find/grp_cs,grp_math,grp_nlin,grp_physics,grp_q-bio,grp_stat/1/all:+AND+b+AND+436+GJ/0/1/0/all/0/1>

Here one can find all ADS papers referencing GJ 436:
<http://adsabs.harvard.edu/cgi-bin/nph-abs_connect?db_key=AST&db_key=PHY&db_key=PRE&qform=AST&arxiv_sel=astro-ph&arxiv_sel=cond-mat&arxiv_sel=cs&arxiv_sel=gr-qc&arxiv_sel=hep-ex&arxiv_sel=hep-lat&arxiv_sel=hep-ph&arxiv_sel=hep-th&arxiv_sel=math&arxiv_sel=math-ph&arxiv_sel=nlin&arxiv_sel=nucl-ex&arxiv_sel=nucl-th&arxiv_sel=physics&arxiv_sel=quant-ph&arxiv_sel=q-bio&sim_query=YES&ned_query=YES&lpi_query=YES&iau_query=YES&obj_req=YES&aut_logic=OR&obj_logic=AND&author=&object=GJ+436&start_mon=&start_year=&end_mon=&end_year=&ttl_logic=OR&title=&txt_logic=OR&text=&nr_to_return=500&start_nr=1&jou_pick=ALL&ref_stems=&data_and=ALL&group_and=ALL&start_entry_day=&start_entry_mon=&start_entry_year=&end_entry_day=&end_entry_mon=&end_entry_year=&min_score=&sort=SCORE&data_type=SHORT&aut_syn=YES&ttl_syn=YES&txt_syn=YES&aut_wt=1.0&obj_wt=1.0&ttl_wt=0.3&txt_wt=3.0&aut_wgt=YES&obj_wgt=YES&ttl_wgt=YES&txt_wgt=YES&ttl_sco=YES&txt_sco=YES&version=1>
and referencing GJ 436 b:
<http://adsabs.harvard.edu/cgi-bin/nph-abs_connect?db_key=AST&db_key=PHY&db_key=PRE&qform=AST&arxiv_sel=astro-ph&arxiv_sel=cond-mat&arxiv_sel=cs&arxiv_sel=gr-qc&arxiv_sel=hep-ex&arxiv_sel=hep-lat&arxiv_sel=hep-ph&arxiv_sel=hep-th&arxiv_sel=math&arxiv_sel=math-ph&arxiv_sel=nlin&arxiv_sel=nucl-ex&arxiv_sel=nucl-th&arxiv_sel=physics&arxiv_sel=quant-ph&arxiv_sel=q-bio&sim_query=YES&ned_query=YES&lpi_query=YES&iau_query=YES&obj_req=YES&aut_logic=OR&obj_logic=AND&author=&object=GJ+436+b&start_mon=&start_year=&end_mon=&end_year=&ttl_logic=OR&title=&txt_logic=OR&text=&nr_to_return=500&start_nr=1&jou_pick=ALL&ref_stems=&data_and=ALL&group_and=ALL&start_entry_day=&start_entry_mon=&start_entry_year=&end_entry_day=&end_entry_mon=&end_entry_year=&min_score=&sort=SCORE&data_type=SHORT&aut_syn=YES&ttl_syn=YES&txt_syn=YES&aut_wt=1.0&obj_wt=1.0&ttl_wt=0.3&txt_wt=3.0&aut_wgt=YES&obj_wgt=YES&ttl_wgt=YES&txt_wgt=YES&ttl_sco=YES&txt_sco=YES&version=1>

The GJ 436 transit paper:
Detection of transits of the nearby hot Neptune GJ 436 b
M. Gillon, F. Pont, B.-O. Demory, et al
http://adsabs.harvard.edu/abs/2007arXiv0705.2219G
http://arxiv.org/abs/0705.2219
http://arxiv.org/pdf/0705.2219

A good starting point for exoplanets is always also:
Extrasolar Planets Encyclopaedia
http://exoplanet.eu
http://exoplanet.eu/star.php?st=GJ+436

Its a high proper motion star as can be seen by blinking the DSS-1
and DSS-2 plates (see attached finder chart by Dagny Looper).
According to Arne its ~ 10pc away and shows a proper motion of
~ 1.5arcsec/year.

Further info see attached emails.

Clear skies
 Wolfgang

-- 
Wolfgang Renz, Karlsruhe, Germany
Rz.BAV = WRe.vsnet = RWG.AAVSO

----- Original Message ----- 
From: "Aaron Price" <aaronp at aavso.org>
To: <aavso-photometry at aavso.org>
Sent: Friday, June 08, 2007 8:24 PM
Subject: [Aavso-photometry] GJ 436 Campaign Web Page

> I've created a web page for the GJ 436b campaign here:
> http://www.aavso.org/news/gj436.shtml
> 
> Right now it just has some useful links. As data comes in
> we'll start to post light curves and more information. 
> One of the most interesting links available there is to Dr.
> Laughlin's blog post about the discovery. Greg writes 
> one of the best astronomy blogs out there. It's grounded,
> yet intense and gets into the nitty gritty details - just 
> what AAVSOers want! He's also a talented writer.
> Highly recommended reading.
> 
> Aaron

----- Original Message ----- 
From: "Greg Laughlin" <laugh at ...>
To: <transitsearch at ucolick.org>
Sent: Wednesday, May 16, 2007 6:10 PM
Subject: [TransitSearch] Gl 436: Important

> Hello Everyone,
> 
> There's been a remarkable discovery by the Swiss group that the 
> Neptune-mass planet
> orbiting the M2V star Gl 436 is transiting with a photometric depth of 
> 0.6%. The period
> of the planet is 2.64 days, and the star is at RA 11:42  +26:42 dec.
> 
> The discovery preprint is at:
> http://xxx.lanl.gov/pdf/0705.2219
> 
> I will be covering this story closely on oklo.org, see, e.g.
> http://oklo.org/?p=213
> 
> The up-to-date transit ephemeris are at:
> http://www.ucolick.org/%7elaugh/GJ436____b.transits.txt
> 
> (the transit is not central, and so the actual duration is of order 1 
> hour, not the 85 minutes
> predicted for a central transit).
> 
> The radial velocity data set for the star indicates that the transiting 
> planet has a significant
> eccentricity. Given the fact that it has a Neptune-like composition, 
> the tidal circularization
> timescale is quite short, and the presence of an eccentric orbit thus 
> strongly indicates
> the presence of additional planets in the system. These can potentially 
> be detected through
> transit, or alternately, and more provocatively through precise timing 
> of the transits of the known
> transiting planet.
> 
> It is therefore very important to obtain as much photometry as possible 
> for this star, both
> to search for additional transiting planets in the system and to obtain 
> light curves during transit
> that can be used for transit timing purposes.
> 
> We will be modifying the systemic console to provide all users with the 
> capability of obtaining
> fully dynamical multi-planet fits to joint light-curve + transit timing 
> + radial velocity data sets. I am envisioning
> a collaborative community-wide effort to potentially make an extremely 
> exciting discovery.
> 
> Stay tuned for more details. I hope you can join this exciting effort. 
> I think that this is the most
> important opportunity that has arisen for small-telescope observers in 
> a very long time.
> 
> with best regards,
> Greg
> 
> Gregory Laughlin
> Dept. of Astronomy and Astrophysics
> UCO/Lick Observatory
> UCSC
> Santa Cruz, CA 95064
> 
> http://www.oklo.org
> laughlin at ucolick.org
> (831) 459-3208

----- Original Message ----- 
From: "Dagny Looper" <dagny at ...>
To: <FrankJ12 at ...>
Cc: <transitsearch at ucolick.org>
Sent: Thursday, May 17, 2007 6:22 AM
Subject: Re: [TransitSearch] Gl 436: Important

> Finderchart is attached.

----- Original Message ----- 
From: "arne" <arne at ...>
To: "Dagny Looper" <dagny at ...>
Cc: <transitsearch at ucolick.org>
Sent: Thursday, May 17, 2007 2:27 PM
Subject: Re: [TransitSearch] GJ 436

> Note that this is a very nearby object (10pc) and therefore
> has high proper motion (about 1.5arcsec/year).  Don't use the
> Simbad coordinates as gospel; look at your own images.
> 
> We are in the process of calibrating the field from our robotic
> telescope at Sonoita Research Observatory (SRO).  Once we have
> calibrated magnitudes for a good set of reference/comparison stars,
> the AAVSO will announce a monitoring campaign on GJ436.  Remember,
> this is a *very* difficult object in that the transits are very
> low amplitude and the eclipsed star is very red.
> Arne

----- Original Message ----- 
From: "arne" <arne at ...>
To: "VALMECA" <valmeca at ...>
Cc: <transitsearch at ucolick.org>
Sent: Thursday, May 17, 2007 9:45 PM
Subject: Re: [TransitSearch] GJ 436

> VALMECA wrote:
>> Hi,
>> 
>> Thanks for the info's, I'll aim my 24"R-C on it this night, do I have to use 
>> the R filter instead of the V for my images?
>> I wait for your answer.
>> Many thanks,too.
> 
> Hi Serge,
> Go as blue as you can; B is great, V is ok, but don't use
> Rc or Ic with the 24-inch.
> 
> This is a 10th magnitude star, and the longer your exposures, the less
> scintillation you will have.  The transit of the known planet takes
> about an hour, so resolutions of 60 seconds or so are just fine.
> The transit depth is about 0.6percent, or 0.006mag, so it is a tough
> project.  The other reason for going blue is that this is an intrinsically
> red star, which tend to have molecular bands and the like in the redder
> filters, making correlations with other observers more difficult.
> Arne

----- Original Message ----- 
From: "Tonny Vanmunster" <Tonny.Vanmunster at ...>
To: "'Greg Laughlin'" <laugh at ...>; <transitsearch at ucolick.org>
Sent: Friday, May 18, 2007 3:49 AM
Subject: [TransitSearch] Transit observations of exoplanet GJ 436 b at CBABelgium Observatory

> Hi Greg,
> 
> I have just posted my transit observations of the newly discovered
> exoplanet GJ 436 b on my website (www.cbabelgium.com). Rather
> unexpectedly, the skies cleared out this evening over CBA Belgium
> Observatory, shortly before the start of the transit. Photometric con-
> ditions were not ideal (bit of haze), but I started a photometry session
> using a 0.35-m f/6.3 telescope and SBIG ST-7XME CCD camera
> with V filter. The resulting lightcurve clearly shows the full transit.
<http://users.skynet.be/fa079980/non_cv_2007/GJ436b_2007_May_17.htm>
> 
> The actual transit has started a bit later than predicted (on
> Transitsearch.org) and its duration was also a bit shorter than predicted.
> This is in agreement with what you wrote in your email. Based on my
> observations, I found following data :
> 
> - ingress : 2007 May 17 at 23h01m UT
> - egress : 2007 May 17 at 23h53m UT
> - mid-transit : 2007 May 17 at 23h28m UT
> - duration : 52 min
> - depth : 0.007 mag 
> 
> There's also a strange "dip" in the ligth curve near JD +0.41, for which I
> have no direct explanation.
> 
> Best regards,
> Tonny
> 
> Tonny Vanmunster
> CBA Belgium Observatory
> http://www.cbabelgium.com