Observing Ross 128

Observing Ross 128

     For the fourth time in a row now, we find ourselves up against the challenge of isolating an exceptionally faint red dwarf out of the mass of equally faint points of light in our field of view.

      The constellation Virgo is one of the most observed places in the entire sky, thanks to the Virgo Galaxy Cluster contained mostly within its bounds (it spills over somewhat into neighboring Coma Berenices). So you might be excused if it’s never occurred to you to slew a little south and east to check out Ross 128 over at the constellation’s eastern extremities.

     We can start with the brightest star in Virgo – Spica, a lovely beacon of purest white that completes the super-asterism which starts with the handle of the Big Dipper in the far north, continues on through Arcturus in Bootes, and ends with Spica to describe a remarkable arc of stars that spans the entire sky in springtime.  Asterisms are frequently more obviously noticeable than formal constellations. Take for example the Great square, the dominant feature of the autumn sky. For me, this heaven-embracing arc of spring stands with the most remarkable star patterns of all.

     From Spica, it’s no problem at all to spot the 2.74 magnitude Porrima. This star basically ties the whole of Virgo together, representing as it does the base of the neck of the reclining woman which the constellation supposedly represents. Her right arm extends northward from Porrima under the Virgo Cluster as far as the star Vindemiatrix; her left ending at Spica. Eastward, she has inclined her head, made up of a irregular trapezoid of four stars: Zaniah at the southwest corner, Omega Virginis to the north, Nu Virginis to the northeast, and Zavijava (Beta Virginis) completing the figure to the southeast (see here: https://upload.wikimedia.org/wikipedia/commons/thumb/f/f5/Virgo_IAU.svg/1210px-Virgo_IAU.svg.png ). Its 3.1 magnitude makes it the brightest of the four, but not by much. (Of historical interest, on September 21, 1922, Albert Einstein used light from this star visible during a solar eclipse to observationally confirm his calculations determining the speed of light in a vacuum.)

     From Zavijava (Beta Virginis) we will need to trace a line southeast to the magnitude 4.3 star Upsilon Leonis. The distance between these two stars is somewhat less than that between the “pointer stars” of the Big Dipper. This should still be within the realm of naked eye visibility, even from Howard County. But from here on in, we will require optical aid.

The above illustration indicates the star patterns in the vicinity of Ross 128 below naked eye visibility (figure is not mirror-imaged). As you can see, our star lies slightly south of the line between Beta Virginis and Upsilon Leonis. A series of 6th and 7th magnitude stars south of these two principle skymarks help us to isolate the search area. The 6th magnitude star almost directly south of Beta Virginis is HD 102634. Almost exactly half way, but not quite on a direct line, between these two stars you’ll find a very distinctive half-circle pattern of stars ranging from 9th to 12th magnitude.

This semicircle is almost impossible to miss (it practically leaped out of the eyepiece at me the first time I looked for it), and will be our principle aid in zeroing in on Ross 128. Note that the stars making up the right half of this asterism are distinctly brighter than those of the left half (speaking here of a mirror-imaged telescopic view). Centering it in our field of view, to its immediate left can be seen a colorless 10.9 magnitude star with the lovely name of TYC 272-739-1. Try as I might, I could discover nothing of interest about this star. But it does point to our goal, for just beyond it and again to the left, is the distinctively red and one full magnitude dimmer Ross 128, the object of our search.

     As I said above, spend some time taking a good, hard look at this star after taking all the trouble to find it. For that dim speck of light, lost amid the more brilliant splendors that crowd in on it from every side, is what most of our universe looks like. It is we who are the exception to the rule. Our bright, gaudy and relatively massive star will race through its brief life of 10 billion years or so before swelling up into a bloated, unstable red giant, then shedding its outer layers to treat alien astronomers to a brief display of a flashy planetary nebula, before finally collapsing into a pitiful white dwarf brooding on past glories like a faded movie star.