Warm Ice Giant GJ 3470b: Revised System Parameters From New

MulB-band Photometry

Lauren Biddle The University of Arizona

Biddle et al. (Accepted at MNRAS)

Kyle A. Pearson (University of Arizona), Ian J. M. Crosseld (Max Planck InsBtut fur Astronomie), Benjamin J. Fulton (University of Hawaii), Simona Ciceri (Max Planck InsBtut fur Astronomie), Jason Eastman (Las Cumbres Global

Telescope Network), Travis Barman (Lunar and Planetary Laboratory), Andrew W. Mann (University of Texas at AusBn), Gregory W. Henry (Tennessee State University), Andrew W. Howard (University of Hawaii), Michael H. Williamson (Tennessee State University), Evan Sinuko (University of Hawaii), Diana Dragomir (Las Cumbres Global Telescope

Network), Laura Vican (UCLA), Luigi Mancini (Max Planck InsBtute fur Astronomie), John Southworth (Keele University), Adam Greenberg (UCLA), Jake D. Turner (University of Virginia), Robert Thompson (Lunar and Planetary Laboratory), Brian W. Taylor (Boston University), Stephen E. Levine(Northern Arizona University; Massachuse^s

InsBtute of Technology), Ma^hew W. Webber (Massachuse^s InsBtute of Technology)

An Extra Thank You

Why GJ 3470b?

Earth 1 M

GJ 1214b 6.6 M Neptune 17 M GJ 3470b 14 M

Belongs to an underrepresented class of exoplanets transiBng small, cool stars. Others including: GJ 436b HD 97658b

Our understanding of these bodies may improve current models of planet formaBon and evoluBon.

The Widely Known Transit Method

Image Credit: Falhad Sulheria, novacelesBa.com

The most prominent physical parameter we can deduce from these observaBons is the Radius of the planet.

Coupled with RV observaBons we can calculate the bulk density.

The Many Uses of Transit Photometry: Transit Timing

Mazeh et al. (2013)

We can use many transit observaBons of a single object in search for addiBonal bodies.

The signal we look for are Transit Timing VariaBons (TTVs)

TTVs are a result of the gravitaBonal pull of another planet on the transiBng planet.

The Many Uses of Transit Photometry: Transit Spectroscopy

Brightne

ss

Brightne

ss

Time

Time

Rp(1)

Rp(2)

Kreidberg et al. (2013)

The Many Uses of Transit Photometry: Transit Spectroscopy

But the Host Star is Important, Too!

Biddle et al. (In review)

We obtained spectra with IRTF/SpeX and the UH 2.2m/SNIFS. Te = 3682 +/- 60 K Distance = 28.2 +/- 2.53

R* = 0.48 +/- 0.04 M* = 0.51 +/- 0.06

Long Term Stellar Monitoring

Stellar rotaBon period = 20.70 +/ 0.15 days

Brightness within the error of our measurements

ObservaBons

Transits 1-3: Bonls et al. (2012) Transits 4-7: Fukui et al. (2013)

Transits 8-21: Biddle et al. (In review)

Search for AddiBonal Bodies with TTVs

Limits for which there are no

transit varia8ons.

= analyzed homogeneously in this work = analyzed separately*

*Separate analysis by Demory et al. (2013), Crosseld et al. (2013) Biddle et al. (In review)

-20 0 20 40 60 80 100 120 140Orbit Number

-5

0

5

10O-

C (m

inut

es)

GJ 3470b Atmospheric Models

Well t: H2 atmosphere Standard chemical abundances and equilibrium chemistry Rayleigh sca^ering haze.

No evidence: disequilibrium chemistry or haze free condiBons

Biddle et al. (In review) (1) Crosseld et al. (2013); (2) Demory et al. (2013)

(1) (2)

2 = 19.15 2 = 8.80 2 = 15.27

Conclusions GJ 3470b is important because it may help improve our understanding of formaBon and evoluBon of Neptune-sized exoplanets

Using transit photometry we can look for indicaBons of addiBonal bodies in the system in addiBon to characterizing the planetary atmosphere with TTVs

All measurements to date show no indicaBon of disequilibrium atmospheric chemistry

Thank You.