Home of MagAO and MagAO-X.
Today was our first night of Arizona engineering. We have a lot of calibrations to do, with all of our modes, but sadly it was cloudy and windy out of the North. I hear it’s because of El Nino.
Sunset:
These pictures are all from the past week or so. Which one is Tucson and which one is LCO?
Yesterday’s song was Glitch Mob, which reminded me of flash mobs:
Clio is cold, thanks to Mauricio Navarette’s help with the liquid nitrogen. He brought a longer hose, showed me how to clear out the warm air before pumping it in, and filled Clio when ever he could today.
Jared and I went for a ride in the new Clay car with Michigan grad students Jeb Bailey and Yingyi Song to the GMT site. Buell posted about the ground-breaking ceremony last week — it wasn’t just ceremonial, there is actual construction going on up there. It’s a huge flat Cerro Campanas and we found some rocks that ring like bells as the name says.
Yesterday’s song of the day was a pop parody about science. Today’s song of the day is a pop parody about doing science:
Based on the issues Jared has been having with the Adsec Supervisor harddrives, we decided to test booting off the Clio harddrive spare that Vanessa and I made a few runs back. Laird and I supervised the crew moving the ASM to the top. Mauricio and I began pumping down Clio. And Jared continued to trouble shoot his various computers and cameras. Pictures:
Yesterday’s song of the day was by Kesha, so today’s is a fun Kesha parody by Jank about Astrobiology:
2015B is upon us. I’m getting ready to leave in a couple days. My parents drove down from NM for a visit since I won’t be seeing them at any of the upcoming holidays. We hiked to the top of Blackett’s Ridge — a 1700-foot elevation gain — and it was a beautiful day:
A nice way to enjoy fall in Tucson before the summer run in LCO!
Blog Rules:
1. Every post of the day must have a song of the day.
2. If the post of the day is the first one for 2015B, the song of the day is at the poster’s discretion.
3. If the post of the day is not the first post of the day for 2015B, the song of the day for post N must be related somehow to the song from day N-1.
3.1. The connection must be clearly stated.
4. Any other covers, etc. are allowed, just be clear about which song is the official song of the day.
That’s all folks.
I am happy to announce the acceptance of Magellan Adaptive Optics first-light observations of the exoplanet beta Pic b. Paper II by the Astrophysical Journal. This paper presents the 0.9-5 micron spectral energy distribution (SED) of young giant exoplanet beta Pic b. We carefully calibrated Clio (see the Appendix), analyzed our photometry, combined it with other works’ photometry, and measured the total brightness of the planet at all wavelengths — the bolometric luminosity. Here are the images of the star and planet:
Here is the star’s SED and the planet’s SED:
Bottom: SED of the planet (Figure 3 from the paper).
We measured the bolometric luminosity empirically by integrating the SED and extending with a best-fit blackbody:
This is the first time the luminosity has been measured empirically, and it is in agreement with the luminosity from models but about 20% brighter than brown dwarfs of a similar temperature (the bolometric correction, abbreviated B.C. in the table):
Abstract: Young giant exoplanets are a unique laboratory for understanding cool, low-gravity atmospheres. A quintessential example is the massive extrasolar planet beta Pic b, which is 9 AU from and embedded in the debris disk of the young nearby A6V star beta Pictoris. We observed the system with first light of the Magellan Adaptive Optics (MagAO) system. In Paper I we presented the first CCD detection of this planet with MagAO+VisAO. Here we present four MagAO+Clio images of beta Pic b at 3.1 um, 3.3 um, L’, and M’, including the first observation in the fundamental CH_4 band. To remove systematic errors from the spectral energy distribution (SED), we re-calibrate the literature photometry and combine it with our own data, for a total of 22 independent measurements at 16 passbands from 0.99-4.8 um. Atmosphere models demonstrate the planet is cloudy but are degenerate in effective temperature and radius. The measured SED now covers > 80% of the planet’s energy, so we approach the bolometric luminosity empirically. We calculate the luminosity by extending the measured SED with a blackbody and integrating to find log(L_{bol}/L_{Sun}) = -3.78 +- 0.03. From our bolometric luminosity and an age of 23 +- 3 Myr, hot-start evolutionary tracks give a mass of 12.7 +- 0.3 M_{Jup}, radius of 1.45 +- 0.02 R_{Jup}, and T_{eff} of 1708 +- 23 K (model-dependent errors not included). Our empirically-determined luminosity is in agreement with values from atmospheric models (typically -3.8 dex), but brighter than values from the field-dwarf bolometric correction (typically -3.9 dex), illustrating the limitations in comparing young exoplanets to old brown dwarfs.
K. Morzinski et al., “Magellan Adaptive Optics first-light observations of the exoplanet beta Pic b. II. 3-5 micron direct imaging with MagAO+Clio, and the empirical bolometric luminosity of a self-luminous giant planet”
ApJ 815, 108, 2015 ; ArXiv Preprint ; ApJ