K2 News and Results
Page 4 of 11 • Share •
Page 4 of 11 • 1, 2, 3, 4, 5 ... 9, 10, 11
Re: K2 News and Results
I'm part of an association for popular science in France named Planète-Sciences and I am able to pilot the 600mm TJMS telescope of our observatory next to Paris (but havent touched it for half a year
). I received a mail and I'm very proud that amateur astronomers at our observatory have validated a candidate from K2 mission.
The observation was made by Olivier Désormières, jean Michel Vienney and Bruno Dauchet and mandated by Alexandre Santerne. In the mail I received, the star is TYC 1818-1428-1 and the exoplanet is named K2 (9792).

The observation was made by Olivier Désormières, jean Michel Vienney and Bruno Dauchet and mandated by Alexandre Santerne. In the mail I received, the star is TYC 1818-1428-1 and the exoplanet is named K2 (9792).
Stalker- Jovian
- Number of posts : 538
Age : 28
Location : Paris, France
Registration date : 2008-06-16
Re: K2 News and Results
Félicitations !!!!!
C'est quel observatoire ?
C'est quel observatoire ?
Led_Zep- Jovian
- Number of posts : 600
Location : France
Registration date : 2011-09-09
Re: K2 News and Results
C'est le centre d'astronomie Jean-Marc Salomon, situé à la base de loisir de Buthiers (we shouldnt talk french here^^)
Stalker- Jovian
- Number of posts : 538
Age : 28
Location : Paris, France
Registration date : 2008-06-16
Re: K2 News and Results
Mais, je comprendre (un peu)! "une foule de trois", non? 
Looking at things on planet hunters, this looks like a Hot Jupiter around an early-K dwarf (EPIC 211089792). I remember avoiding looking at it as the target is a close, probably physical binary, so I imagine that's what the ground-based observations were for.
Anyway, congratulations!!

Looking at things on planet hunters, this looks like a Hot Jupiter around an early-K dwarf (EPIC 211089792). I remember avoiding looking at it as the target is a close, probably physical binary, so I imagine that's what the ground-based observations were for.
Anyway, congratulations!!
Shellface- Neptune-Mass
- Number of posts : 283
Location : g2 17.∞ 997 t
Registration date : 2013-02-14
Re: K2 News and Results
EPIC210957318b and EPIC212110888b: two inflated hot-Jupiters around Solar-type stars
http://arxiv.org/abs/1601.07635
EPIC211089792 b: an aligned and inflated hot jupiter in a young visual binary
http://arxiv.org/abs/1601.07680
Confirmation of Two Hot Jupiters from K2 Campaign 4
http://arxiv.org/abs/1601.07844
http://arxiv.org/abs/1601.07635
EPIC211089792 b: an aligned and inflated hot jupiter in a young visual binary
http://arxiv.org/abs/1601.07680
Confirmation of Two Hot Jupiters from K2 Campaign 4
http://arxiv.org/abs/1601.07844
_________________
Caps Lock: Cruise control for 'Cool'!
Sirius_Alpha- Admin
- Number of posts : 3799
Location : Earth
Registration date : 2008-04-06
Re: K2 News and Results
Stalker wrote:I'm part of an association for popular science in France named Planète-Sciences and I am able to pilot the 600mm TJMS telescope of our observatory next to Paris (but havent touched it for half a year). I received a mail and I'm very proud that amateur astronomers at our observatory have validated a candidate from K2 mission.
The observation was made by Olivier Désormières, jean Michel Vienney and Bruno Dauchet and mandated by Alexandre Santerne. In the mail I received, the star is TYC 1818-1428-1 and the exoplanet is named K2 (9792).
http://arxiv.org/abs/1601.07680
EPIC211089792 b: an aligned and inflated hot jupiter in a young visual binary

Led_Zep- Jovian
- Number of posts : 600
Location : France
Registration date : 2011-09-09
Re: K2 News and Results
Congratulations!
Lazarus- dF star
- Number of posts : 3069
Registration date : 2008-06-12
Re: K2 News and Results
Seconded! Congratulations, Stalker!
_________________
Caps Lock: Cruise control for 'Cool'!
Sirius_Alpha- Admin
- Number of posts : 3799
Location : Earth
Registration date : 2008-04-06
Re: K2 News and Results
Sadly i didnt do anything, the congratulations goes to the cited astronomers.
Stalker- Jovian
- Number of posts : 538
Age : 28
Location : Paris, France
Registration date : 2008-06-16
Re: K2 News and Results
The K2-ESPRINT Project IV: A Hot Jupiter in a Prograde Orbit with a Possible Stellar Companion
http://arxiv.org/abs/1602.00638
http://arxiv.org/abs/1602.00638
We report on the detection and early characterization of a hot Jupiter in a 3-day orbit around EPIC 212110888, a metal-rich F-type star located in the K2 Cycle 5 field. Our follow-up campaign involves precise radial velocity (RV) measurements and high-contrast imaging using multiple facilities. The absence of a bright nearby source in our high-contrast data suggests that the transit-like signals are not due to light variations from such a contaminant star. Our intensive RV measurements show that EPIC 212110888b has a mass of 1.726±0.085MJ, confirming its status as a planet. We also detect the Rossiter-McLaughlin effect for EPIC 212110888b and show that the system has a good spin-orbit alignment (λ=4+11−10 degrees). High-contrast images obtained by the HiCIAO camera on the Subaru 8.2-m telescope reveal a faint companion candidate (ΔmH=6.19±0.11) at a separation of $\sim 0\farcs36$. Follow-up observations are needed to confirm that the companion candidate is physically associated with EPIC 212110888. EPIC 212110888b appears to be an example of a typical ``hot Jupiter,' albeit one which can be precisely characterized using a combination of K2 photometry and ground-based follow-up.
_________________
Caps Lock: Cruise control for 'Cool'!
Sirius_Alpha- Admin
- Number of posts : 3799
Location : Earth
Registration date : 2008-04-06
tommi59- Jovian
- Number of posts : 565
Age : 41
Location : Baile Atha Cliath
Registration date : 2010-07-31
Re: K2 News and Results
Mc Donald Obs. press release about K2-25b (EPIC 210490365) :
http://mcdonaldobservatory.org/news/releases/20160224
http://mcdonaldobservatory.org/news/releases/20160224
Led_Zep- Jovian
- Number of posts : 600
Location : France
Registration date : 2011-09-09
Sirius_Alpha- Admin
- Number of posts : 3799
Location : Earth
Registration date : 2008-04-06
Re: K2 News and Results
http://arxiv.org/abs/1603.01721
An independent discovery of two hot Jupiters from the K2 mission
We report the discovery of two hot Jupiters using photometry from Campaigns 4 and 5 of the two-wheeled Kepler (K2) mission. EPIC210957318b has a mass of 0.65±0.14MJ, a radius of 1.070±0.018RJ and transits its G dwarf (Teff=5675±50 K), slightly metal rich ([Fe/H]=+0.06±0.04 dex) host star in a 4.1 days circular orbit. EPIC212110888b has a mass of 1.63±0.12MJ, a radius of 1.38±0.014RJ and has an orbital period of 3.0 days in which it orbits a late F dwarf (Teff=6149±55 K) solar metallicity star. Both planets were validated probabilistically and confirmed via precision radial velocity (RV) measurements. They have physical and orbital properties similar to the ones of the already uncovered population of hot Jupiters and are well-suited candidates for further orbital and atmospheric characterization via detailed follow-up observations.
An independent discovery of two hot Jupiters from the K2 mission
We report the discovery of two hot Jupiters using photometry from Campaigns 4 and 5 of the two-wheeled Kepler (K2) mission. EPIC210957318b has a mass of 0.65±0.14MJ, a radius of 1.070±0.018RJ and transits its G dwarf (Teff=5675±50 K), slightly metal rich ([Fe/H]=+0.06±0.04 dex) host star in a 4.1 days circular orbit. EPIC212110888b has a mass of 1.63±0.12MJ, a radius of 1.38±0.014RJ and has an orbital period of 3.0 days in which it orbits a late F dwarf (Teff=6149±55 K) solar metallicity star. Both planets were validated probabilistically and confirmed via precision radial velocity (RV) measurements. They have physical and orbital properties similar to the ones of the already uncovered population of hot Jupiters and are well-suited candidates for further orbital and atmospheric characterization via detailed follow-up observations.
Led_Zep- Jovian
- Number of posts : 600
Location : France
Registration date : 2011-09-09
Re: K2 News and Results
http://www.nasa.gov/feature/ames/nasas-k2-mission-the-kepler-space-telescopes-second-chance-to-shine
Press release :
NASA's K2 mission: The Kepler Space Telescope's Second Chance to Shine
Press release :
NASA's K2 mission: The Kepler Space Telescope's Second Chance to Shine
Led_Zep- Jovian
- Number of posts : 600
Location : France
Registration date : 2011-09-09
Re: K2 News and Results
Adams, Jackson & Endl "Ultra Short Period Planets in K2: SuPerPiG Results for Campaigns 0-5"
http://arxiv.org/abs/1603.06488
Possible hints that the K2 planet population may have different characteristics compared to the Kepler population.
http://arxiv.org/abs/1603.06488
Possible hints that the K2 planet population may have different characteristics compared to the Kepler population.
Lazarus- dF star
- Number of posts : 3069
Registration date : 2008-06-12
Re: K2 News and Results
Led_Zep wrote:Stalker wrote:I'm part of an association for popular science in France named Planète-Sciences and I am able to pilot the 600mm TJMS telescope of our observatory next to Paris (but havent touched it for half a year). I received a mail and I'm very proud that amateur astronomers at our observatory have validated a candidate from K2 mission.
The observation was made by Olivier Désormières, jean Michel Vienney and Bruno Dauchet and mandated by Alexandre Santerne. In the mail I received, the star is TYC 1818-1428-1 and the exoplanet is named K2 (9792).
http://arxiv.org/abs/1601.07680
EPIC211089792 b: an aligned and inflated hot jupiter in a young visual binary
![]()
EPIC 9792 is now K2-29b/WASP 152b. Soon in the Astrophysical Journal.
Stalker- Jovian
- Number of posts : 538
Age : 28
Location : Paris, France
Registration date : 2008-06-16
Re: K2 News and Results
Mass determinations from RV and TTV for the K2-19 system:
Nespral et al. "Mass determination of K2-19b and K2-19c from radial velocities and transit timing variations"
http://arxiv.org/abs/1604.01265
Fits with an emerging trend that TTV-derived masses are systematically lower than RV-derived masses.
Nespral et al. "Mass determination of K2-19b and K2-19c from radial velocities and transit timing variations"
http://arxiv.org/abs/1604.01265
Fits with an emerging trend that TTV-derived masses are systematically lower than RV-derived masses.
Considering the sparsity of TTV measurements that are supported by RV measurements, this work certainly implies that mass determinations from TTV measurements continue to have to be taken with caution, until a better understanding about the causes that may generate any systematics between RV and TTV derived planet masses is achieved.
Lazarus- dF star
- Number of posts : 3069
Registration date : 2008-06-12
Re: K2 News and Results
Doppler Monitoring of five K2 Transiting Planetary Systems
http://arxiv.org/abs/1604.01413
http://arxiv.org/abs/1604.01413
_________________
Caps Lock: Cruise control for 'Cool'!
Sirius_Alpha- Admin
- Number of posts : 3799
Location : Earth
Registration date : 2008-04-06
Re: K2 News and Results
Not often that you see a run-on abstract.
There's quite a large discrepancy for the K2-19 results between these papers, which needs some inspection. Looking at the masses:
(errors have been averaged to symmetry for simplicity)
These disagree with each other by a factor of ~2 in opposite directions, which is quite severe.
I cannot currently do any RV modelling, so for the time being I can only conjecture the cause of this issue. Nespral et al. do not consider the effects of stellar rotational activity, which Dai et al. observe as their most significant signal; they also barely consider planet c in the RVs, which may not be appropriate. Though Dai et al. do treat for the rotational signal, they note that the way in which they do it (cutting the dataset into sections) may not be valid considering the modest ratio between Pc and Prot, which I agree with. This may lead to an overestimate of the semi-amplitude for c.
Barros et al. (2015) give the ratio mc/mb = 0.42 ± 0.12 based on TTVs, which should be accurate as long as gravity works as we think it does. For the above results, mc/mb = 0.16 +0.09-0.07 and 0.90 +0.39-0.35 , respectively. The Nespral et al. value is clearly too small, while the Dai et al. value is too large, to lower precision. This should probably be interpreted as an overestimation of mb by Nespral et al., and an overestimation of mc by Dai et al.
As Dai et al.'s RV dataset is much larger and more precise than Nespral et al.'s, I would suggest that their result is probably the truer of the two. I expect a better result could be reached with improved modelling.
There's quite a large discrepancy for the K2-19 results between these papers, which needs some inspection. Looking at the masses:
mb (M⊕) | mc (M⊕) | |
Nespral et al. | 59.5 ± 9.3 | 9.7 ± 3.0 |
Dai et al. | 28.5 ± 5.2 | 25.6 ± 7.1 |
These disagree with each other by a factor of ~2 in opposite directions, which is quite severe.
I cannot currently do any RV modelling, so for the time being I can only conjecture the cause of this issue. Nespral et al. do not consider the effects of stellar rotational activity, which Dai et al. observe as their most significant signal; they also barely consider planet c in the RVs, which may not be appropriate. Though Dai et al. do treat for the rotational signal, they note that the way in which they do it (cutting the dataset into sections) may not be valid considering the modest ratio between Pc and Prot, which I agree with. This may lead to an overestimate of the semi-amplitude for c.
Barros et al. (2015) give the ratio mc/mb = 0.42 ± 0.12 based on TTVs, which should be accurate as long as gravity works as we think it does. For the above results, mc/mb = 0.16 +0.09-0.07 and 0.90 +0.39-0.35 , respectively. The Nespral et al. value is clearly too small, while the Dai et al. value is too large, to lower precision. This should probably be interpreted as an overestimation of mb by Nespral et al., and an overestimation of mc by Dai et al.
As Dai et al.'s RV dataset is much larger and more precise than Nespral et al.'s, I would suggest that their result is probably the truer of the two. I expect a better result could be reached with improved modelling.
Shellface- Neptune-Mass
- Number of posts : 283
Location : g2 17.∞ 997 t
Registration date : 2013-02-14
Re: K2 News and Results
The discrepancy is even worse when you consider the RV-only solution from the Nespral et al. paper, which gives K=24.8±2.3 m/s and mb = 71.7±6.3 Earth masses.
Lazarus- dF star
- Number of posts : 3069
Registration date : 2008-06-12
Re: K2 News and Results
I personally still waiting for precise mass measurement for Kepler 2-3 planets especially c , d as it looks like d is first confirmed rocky planets in HZ around other star than sun and significant difference in density composition between c and d can confirm threshold between rocky and gassy planets
tommi59- Jovian
- Number of posts : 565
Age : 41
Location : Baile Atha Cliath
Registration date : 2010-07-31
Re: K2 News and Results
Damned….
http://www.nasa.gov/feature/mission-manager-update-kepler-spacecraft-in-emergency-mode
Mission Manager Update: Kepler spacecraft in emergency mode

http://www.nasa.gov/feature/mission-manager-update-kepler-spacecraft-in-emergency-mode
Mission Manager Update: Kepler spacecraft in emergency mode
Led_Zep- Jovian
- Number of posts : 600
Location : France
Registration date : 2011-09-09
Re: K2 News and Results
Ouch... was looking forward to seeing what K2 could do as regards microlensing... 

Lazarus- dF star
- Number of posts : 3069
Registration date : 2008-06-12
Re: K2 News and Results
Kepler is now recovered and stable.
http://www.nasa.gov/feature/mission-manager-update-kepler-recovered-from-emergency-and-stable
System checks expected for the rest of this week, then hopefully it can begin the microlensing observations.
http://www.nasa.gov/feature/mission-manager-update-kepler-recovered-from-emergency-and-stable
System checks expected for the rest of this week, then hopefully it can begin the microlensing observations.
Lazarus- dF star
- Number of posts : 3069
Registration date : 2008-06-12
Page 4 of 11 • 1, 2, 3, 4, 5 ... 9, 10, 11
Page 4 of 11
Permissions in this forum:
You cannot reply to topics in this forum
|
|