VisAO and the WFS got a much needed spring cleaning today. We also installed some new filters.
Laird works at installing the new H-alfa filter and our new coronagraphic spots.
Jared and Alfio installed a new more powerful Y-stage motor. This motor has to lift the W-unit against gravity, and the old one was under-powered and so was failing. These motors are very powerful, even the old one, so it is very nerve racking to mess around with them. We had a stressful morning.
Alfio agonizes over the settings for our new motor (that’s it sitting next to him).
T.J. and Katie buttoned up Clio today.
This is the inside of the Clio dewar just before it was buttoned up.Clio being lifted back onto its cart.
The weather has been gorgeous, and we’re seeing lots of locals out and about.
It was a double Viscacha day.This guy is still hanging around. He’s not scared of me, but he doesn’t really want to be friends either.These clowns showed up this afternoon. They always look like they’re up to no good.
Here’s the song of the day. We have spent so much time here it now feels like we’re coming home when we get off the plane in La Serena.
MagAO is back! Katie, T.J., and Jared arrived at LCO last night to begin preparing for our first official science run. Our instrument was offered to the Magellan wide community, who came up with more great ideas than we have time for. We’re taking data for astronomers from all over the world. Stand by for some more great MagAO+VisAO+Clio2 science!
We don’t go on sky until April 1 (no kidding), but we have lots to do to get ready. Katie and T.J. are opening up Clio2 to install and rearrange filters. Jared, Laird, and Alfio (who are coming in the next few days), are replacing some motors in the NAS, as well as upgrading some filters in VisAO.
It’s been a while since we’ve seen a horse up this far on the mountain:
There were a few more around, but this guy was right next to the road when we pulled up.
We’re going to try something new on this run. We’ll have a song-of-the-day, picked by whoever writes the blog post. Here’s my choice for the begining of our 2014A semester campaign.
There are a number of factors that have pushed extrasolar planet imagers to work in the infrared. The first is that young planets are very hot, so they are brighter in the infrared. In fact, they become very faint at shorter “optical” wavelengths. The second factor is that adaptive optics (AO), the technology we use to image exoplanets, has normally worked better in the infrared. You could say that the stars twinkle less there. But to know as much as we can about exoplanets and their atmospheres, we want to image them at as many wavelengths as we can. So we used MagAO’s VisAO camera to image the extrasolar planet beta Pictoris b with our CCD. This is the first time that has been done from the ground, and shows that we are pushing the capabilities of AO to ever shorter (and more difficult) wavelengths.
An image of the exoplanet Beta Pictoris b made with the Magellan Adaptive Optics (MagAO) VisAO camera. This image was made using a CCD camera, which is essentially the same technology as a cell phone camera. The planet is nearly 100,000 times fainter than its star, and orbits its star at roughly the same distance as Saturn from our Sun.
Abstract: We present the first ground-based CCD (λ<1μm) image of an extrasolar planet. Using MagAO's VisAO camera we detected the extrasolar giant planet (EGP) β Pictoris b in Y-short (YS, 0.985 μm), at a separation of 0.470±0.010′′ and a contrast of (1.63±0.49)×10−5. This detection has a signal-to-noise ratio of 4.1, with an empirically estimated upper-limit on false alarm probability of 1.0%. We also present new photometry from the NICI instrument on the Gemini-South telescope, in CH4S,1% (1.58 μm), KS (2.18μm), and Kcont (2.27 μm). A thorough analysis of our photometry combined with previous measurements yields an estimated near-IR spectral type of L2.5±1.5, consistent with previous estimates. We estimate log(Lbol/LSun) = −3.86±0.04, which is consistent with prior estimates for β Pic b and with field early-L brown dwarfs. This yields a hot-start mass estimate of 11.9±0.7 MJup for an age of 21±4 Myr, with an upper limit below the deuterium burning mass. Our Lbol based hot-start estimate for temperature is Teff=1643±32 K (not including model dependent uncertainty). Due to the large corresponding model-derived radius of R=1.43±0.02 RJup, this Teff is ∼250 K cooler than would be expected for a field L2.5 brown dwarf. Other young, low-gravity (large radius), ultracool dwarfs and directly-imaged EGPs also have lower effective temperatures than are implied by their spectral types. However, such objects tend to be anomalously red in the near-IR compared to field brown dwarfs. In contrast, β Pic b has near-IR colors more typical of an early-L dwarf despite its lower inferred temperature.
For more on our result see:
Males, J. R., et al. "Magellan Adaptive Optics first-light observations of the exoplanet β Pic b. I. Direct imaging in the far-red optical with MagAO+VisAO and in the near-IR with NICI"
ApJ, 786, 32, 2014ADSarxiv preprint
2M1207 b (pronounced two-mass-twelve-oh-seven-bee) is often considered the first directly imaged extrasolar planet. Though its primary star, 2M1207 A, is actually a brown dwarf, b shares many properties with the HR 8799 planets. Andy Skemer analyzed images taken with MagAO+Clio2 and compared the results with images of the HR 8799 planets taken with the LBT. The interesting thing about 2M1207 b is that it doesn’t seem to have methane in its atmosphere — otherwise we wouldn’t have been able to see it since methane should absorb all the light at the wavelength we used.
Imaging 2M1207 b is extremely challenging from a technical standpoint. 2M1207 A is a faint brown dwarf, which doesn’t emit enough visible photons for our wavefront sensor. Instead, we locked on an off-axis (and still faint) star 40″ away from the science target. The result demonstrates that MagAO can produce reasonable Strehl ratio images on targets that are too faint to serve as their own guide-star.
2M1207 A, and its planetary-mass companion, 2M1207 b, the first directly-imaged exoplanet (Chauvin et al. 2004). When 2M1207 b was first discovered, it was noted to have unusually red colors, and to be extremely faint compared to other red (L-type) brown dwarfs. This image, taken by MagAO/Clio at 3.3 micron, would show a dark planet if 2M1207 b had properties similar to “normal” objects. Instead, we find the 2M1207 b is bright at 3.3 microns, suggesting an almost complete lack of methane gas.
Abstract: Gas-giant planets emit a large fraction of their light in the mid-infrared (≳3μm), where photometry and spectroscopy are critical to our understanding of the bulk properties of extrasolar planets. Of particular importance are the L and M-band atmospheric windows (3-5μm), which are the longest wavelengths currently accessible to ground-based, high-contrast imagers. We present binocular LBT AO images of the HR 8799 planetary system in six narrow-band filters from 3-4μm, and a Magellan AO image of the 2M1207 planetary system in a broader 3.3μm band. These systems encompass the five known exoplanets with luminosities consistent with L→T transition brown dwarfs. Our results show that the exoplanets are brighter and have shallower spectral slopes than equivalent temperature brown dwarfs in a wavelength range that contains the methane fundamental absorption feature. For 2M1207 b, we find that thick clouds and non-equilibrium chemistry caused by vertical mixing can explain the object’s appearance. For the HR 8799 planets, we find that the atmospheres must have patchy clouds, along with non-equilibrium chemistry. Together, the presence of a heterogeneous surface and vertical mixing presents a picture of dynamic planetary atmospheres in which both horizontal and vertical motions influence the chemical and condensate profiles.
That was quick. The NAS is all packed up, powered-off, dust covers on, etc. In case you were worried, I poked my head into the clean room and the shell is in one piece.
This guy was walking along with me after lunch:
A Guanaco at LCO
This flower is hanging on precariously by the path to the hotel
A little color
I think I caught one of the pooping culprits in the act today
