The Starry Night, 237

:: home ::
              <<  214  215  216  217  218  219  220  221  222  223  224  225  226  227  228  229  230  231  232  233  234  235 
              236  237  238  239  240  241  242  243  244  245  246  247  248  249  250  251  252  253  254  255  256  >>  SRCH

Travels in North America

11/21/2022. It's easy to imagine
spending an entire season in a few small parts of the sky. The belt and sword of Orion is one, and NGC 7000, the North America Nebula in Cygnus, is another.

In some sense much of this page is a rerun; most of these photos have appeared in the Slow Blog elsewhere, some very recently, but it seems worthwhile to bring them together here under this rubric. They are all details of the North America Nebula and its environs. There will be others.

Here's an overall view of the area with a DSLR and a small refractor. Down below are closer looks at Bermuda, the northern Gulf Coast, the Windward Isles, the Bay of Campeche, and Alberta using the 10-inch Ritchey-Chretien and a cooled CMOS astrocamera.



NGC 7000, The North America Nebula


Click any image below for a bigger, better view.


alberta berm
Details in the Vicinity of
NGC 7000
campeche windward


The Bajamar Star. I'd always supposed this entire complex was illuminated by Deneb, a first magnitude star just off the right side of the overview image at top. I and Edwin Hubble thought so. It turns out that Deneb isn't nearly hot enough to provide the ionizing radiation required to light up and sculpt so much space, so the search was on for another candidate. The star turned out to be a very young O-type giant with a surface temperature of around 40,000K. The heavily obscured star lies behind a dense cloud of dust that blocks all but one out of every 1,600 photons it sends our way. The Bajamar Star is the 11th or 12th magnitude spark shining in the "Bahamas" dead center in this widefield photo:



It's also visible just inside the right edge of the close-up of the Northern Gulf.

The paper that identified the star appeared in "Astronomy and Astrophysics" in 2005. Fifteen years later, data from the Gaia satellite allowed the star's nature and place in space to be refined in this paper. In 2016, Apellaniz et al (11 more authors) christened it "the Bajamar Star" in the course of a survey of O-type stars published in the ApJ. This is footnote 19: "We adopt the name 'Bajamar Star' for the object due to its position relative to the North America Nebula, just to the east of the 'Florida Peninsula.' 'Islas de Bajamar,' meaning 'low-tide islands' in Spanish, was the original name of the Bahamas islands because many of them are only easily seen from a ship during low tide."

For a dose of doubt about its etymology, consult the ultimate source of truth on the intertubes: "Tourist guides [to the Bahamas] often state that the name comes from the Spanish baja mar ('shallow sea'). Wolfgang Ahrens of York University argues that this is a folk etymology. Alternatively, it may originate from Guanahani, a local name of unclear meaning." Thus spake Wikipedia.

The dozen authors of the 2016 paper identify it as a double star based on the variability of certain spectral lines and its inconstant radial velocity.




:: top ::







                   © 2022, David Cortner