A “Star” That Wasn’t Supposed to be There

I got a surprise birthday present on the night of October 9, the day before my birthday. A combination of technology and an effect of sunlight observed at night offered me this unexpected “gift” out in the Berkshires in western Massachusetts at Arunah Hill, the great nature and astronomy club in a remote, wonderfully dark rural area that is in southwest Cummington, Mass. The club’s property comprises about 70 acres with the highest elevation point at over 2,000 feet. Arunah Hill lies 2.5 miles south of route 9, roughly two-thirds of the way from Northampton WNW to Pittsfield at a location chosen primarily for its excellent night sky observing combined with a relatively high elevation. (History of the club’s founding and development is a story for another time.) Neighboring towns are Worthington to the south, Peru to the west, and Windsor to the northwest. Skyscrapers’ John Kocur is a member at Arunah, as am I. The site is widely regarded by serious observers to be among the very best spots available for amateur astronomy throughout southern to central New England, on a par with Stellafane in Springfield, Vermont.

Scratch any astronomy gathering and you’re bound to find friendly, cordial people with whom to associate. On the night mentioned I was fortunate to be among good company in the personages of John Kocur and his friends Barry and Frank. Barry, a director at Arunah, had two telescopes set up, the larger of which was a 16” Dobsonian reflector that is a duplicate of one owned by my good friend and observing partner Tim Dube of East Douglas, Mass. Barry’s other scope was a nifty 5” f/5 Newtonian on a handy, smooth working alt-az mount with good manual slow motion controls and a quality optical finder scope. Such scopes are perfect for the kind of observing I most enjoy and I was pleased to have temporary use of the rich-field reflector, which was well collimated and yielded fine images over a range of magnifications with various eyepieces. Although I generally spend most of my time at Arunah Hill by stargazing naked -eye or with a binocular, I appreciated the convenience of using a telescope and mount that I didn’t even have to set up!

The four of us enjoyed good weather and clear skies that night; experienced Arunah observers would probably have rated the sky at 7.5 to 8.0 on a scale of 1 to 10. A mild, intermittent breeze coupled with ideally dry conditions at the summit clearing resulted in almost no dew over many hours. Temperature was cool but not uncomfortable and the Moon was only two days old. It was roughly around 10:00 pm when I decided to walk downhill a bit to a point perhaps 100 yards from the summit parking lot where the scopes were positioned. I glanced up at central Cetus to check the brightness of Mira (Omicron Ceti), the famous prototypical long-period variable star first noted (officially) and recorded by the German astronomer David Fabricius back in 1596. Mira is the brightest LPV, ranging in magnitude from a record of 2.0 up to 10.1 over a period of just under 332 days. The position is RA 02h 19m 21s, Dec. -02° 59’. At 10° to the southwest of Mira lies the magnitude 3.7 star Zeta Ceti (Baten Kaitos), the easternmost star of a large quadrilateral asterism that somewhat resembles an immensely scaled-up version of the well-known Trapezium multiple star at the heart of M42, the Orion Nebula. Magnitude 3.5 Eta Ceti forms the western tip of the 4-star pattern; the nearby magnitude 3.5 star Tau Ceti marks the southern point. By “nearby”, I’m referring to Tau Ceti’s distance from our Sun of only 11.9 light years. Zeta Ceti is easily identified owing to its naked-eye pairing with Chi Ceti, a magnitude 4.7 star that lies 35’ to the southwest of Zeta. (Chi is itself a wide binocular double with a magnitude 6.9 companion at 184” away.)

Almost immediately upon looking towards Mira and Zeta Ceti, I noted what seemed to be an extra naked-eye star just west of the midpoint between the two stars mentioned. Look for the magnitude 11.1 spiral galaxy NGC 779 on a star atlas to see the approximate location of my “star” that appeared out of place; the galaxy’s position is RA 01h 59m 40s, Dec. -05° 58’. I was stunned and stood “rooted to the spot” to see this aberration, particularly because it didn’t seem to be moving and was brightening gradually as I watched, looking comparable to Zeta Ceti. Mira, by the way, was supposedly rising to a projected peak magnitude of 3.3 or so by around October 15. My first inclination was to imagine this star-like object to be a nova of some kind, but I must admit I resisted the notion almost as quickly as it occurred to me–how could I be that lucky? In any case, after gaping for a few more seconds at something I’d not witnessed before, I turned and ran back up the slope, calling out to my companions to get their scopes ready for this new object in Cetus.

John Kocur and Barry asked me to indicate the star’s position as I rejoined them; I did so, using my green laser. The new “star” was fading somewhat by this time but was still a naked-eye object. We put it in view in three telescopes and were fascinated to watch it move gradually against background stars, but remain fixed in position in the center of an eyepiece field! (Barry’s two scopes were both manually-moved, non-tracking types.) Even at high power in the 16”, the object stayed centered in the field continuously over many minutes. Bear in mind that this was seen in a non-tracking telescope.

Naturally, a telescope that is not tracking stars but is used by an observer in a fixed position on its mount will show stars as constantly moving objects that “drift” across the eyepiece field, first appearing–then disappearing–over a short period of time. The time involved is dependent on the eyepiece’s angular width of field and whatever magnification power is yielded in any given telescope’s focal length. (Divide the scope’s focal length in millimeters by that of the eyepiece being used to determine magnification; a 900mm focal length scope will give you 45x magnification in a 20mm eyepiece.) Short focus scopes will yield much wider, richer fields than others having longer focal lengths, another factor involved in this time consideration of object drift. If we consider a fixed telescope as technically being a part of Earth’s surface and realize that the planet is continually rotating on its axis with respect to the stars, this “drift” of stars across an image field is easily understood. The telescope is being carried along with our spinning Earth, but the stars seemingly remain fixed at their positions on the celestial sphere.

The new object in Cetus had faded in brightness considerably after roughly 20 minutes from the time I first noticed it; we observed its magnitude to begin approximating the average brightnesses of most stars seen in the image fields swept by our fixed scopes. Nonetheless, its initial naked-eye appearance had been impressive and mysterious, comparable perhaps to magnitude 3.7 Zeta Ceti or even a bit The new object in Cetus had faded in brightness considerably after roughly 20 minutes from the time I first noticed it; we observed its magnitude to begin approximating the average brightnesses of most stars seen in the image fields swept by our fixed scopes. Nonetheless, its initial naked-eye appearance had been impressive and mysterious, comparable perhaps to magnitude 3.7 Zeta Ceti or even a bit brighter. Both Barry and John came up with the best, most plausible explanation for what we saw before it occurred to me; I was completely flummoxed. They conjectured that a point of light that looked like a star but stayed fixed in the center of an eyepiece field, amid background stars that did continually drift across the field, had to be a geosynchronous satellite orbiting Earth from a seemingly fixed position on the sky with respect to points on the ground. Such satellites occupy orbits typically in excess of 22,000 miles in altitude; their orbital speed rate closely matches that of Earth’s rotation and they therefore appear to “hang” in the sky as opposed to most other satellites we customarily observe to move across the sky in their considerably closer Earth orbits. Geosynchronous satellites orbit close to Earth’s equatorial plane.

The flaring in brightness followed by a gradual dimming would’ve been explained by the satellite’s changing position with respect to sunlight reflected from its body– its attitude in orbit simply reflected more sunlight at certain times than at other times, and it may have been “tumbling” somewhat. At 22,000-plus miles out, the geosynchronous satellite was evidently able to be illuminated by the Sun even though local time was 10:00 to 10:30 pm EDT, approximately. (The time is a rough guess and may have been a bit earlier; I neglected to take note that evening.) I told this story to Jim Hendrickson during a conversation at Ladd Observatory on October 12. Jim asked if the satellite was close to Dec. -06°. He’d heard that was the zone of declination on the sky in which such satellites would be restricted, a fact of which I was unaware. A subsequent check of a star atlas confirmed my sighting to have appeared at just about Dec. -06°, just as Jim had figured! This seemed to bear out the geosynchronous satellite explanation nicely.

As if all this observing activity wasn’t enough, I saw a second such object just shortly after we’d finished viewing the first. I estimate its position to have been about RA 01h 40m, Dec. -06° 30’, marking the northern tip of a triangle involving the aforementioned Zeta Ceti to the southeast and magnitude 3.6 Theta Ceti to the west, which is the northern star of that 4-star asterism in Cetus I described earlier. All in all, a great observing treat unlike anything I’d ever seen, and a nice birthday gift from the night sky to my own eyes.

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