T Pyxidis is a curious recurrent nova whose long-term behavior is not yet well understood. Originally observed in 1890 as a nova, it recurred a few times in the early 20th century but its recurrence time seemed to increase. After the last outburst in 1966, many astronomers expected...
July 18, 2010 - 12:20pm
TT Ari is a cataclysmic variable of the VY Sculptoris class. The VY Scl stars typically remain in a high state like the nova-like variables, and do not show outbursts like those of dwarf novae. What makes them different from the novalikes is that they occasionally undergo deep...
November 13, 2011 - 3:32pm
TX Cam is a long-period Mira variable with highly variable amplitude. It's also a known bright IR source and has strong maser emission, both of which come from the mass that's being shed by this rapidly evolving star. The long-period Miras are interesting objects because...
January 22, 2013 - 3:55pm
TX Persei is an RV Tauri variable of the RVa subclass, meaning it maintains a constant mean brightness without a long secondary period seen in the RVb subclasses. Like many RV Tauri stars, the light curve shows some evidence of periodicity, with reasonably regular dips in brightness...
March 22, 2012 - 1:57pm
U Aquarii belongs to the RCB class of stars. R Coronae Borealis stars (RCBs) are a small group of hydrogen poor, carbon rich supergiants that decline in brightness unpredictably and rapidly by up to 9 magnitudes, and remain at or near minimum light for several weeks or months, even years in...
October 21, 2010 - 6:22pm
U Geminorum is the class prototype for the dwarf nova subclass of cataclysmic variables. Discovered in 1855 by British astronomer J.R. Hind, U Gem has intrigued generations of astronomers, and remains a fascinating (and scientifically useful) target to this day. U Gem, like all of...
September 10, 2012 - 2:39pm
U Mic is a classic mira variable with a period close to one year, a reasonably stable light curve, and strong amplitude of more than five magnitudes in the visual (from 14th to 9th or better). Unfortunately it's also becoming less-frequently observed by visual observers as time goes...
July 18, 2010 - 12:22pm
U Mon is an example of an RV Tauri star -- a pulsating variable showing pulsations with short-term regularity but with long-term irregular variations. U Mon has a pulsation period (the length of time between two minima of equal depth) of around 92 days. However, its long-term light...
October 28, 2011 - 8:35am
This weeks light curve of the week highlights one of the challenges we face as a community that's attempting to collect long-term light curves. U Tucanae is a bright southern Mira variable with a reasonably good chart and a decades-long history of observations by visual observers....
October 8, 2010 - 2:24pm
V Hydrae is a semiregular variable with a curious light curve. The star appears to undergo cyclical dimming events with a period of 15 to 20 years. The underlying pulsations don't seem to change much during these dimming events, which suggests that the star may be dimmed by...
September 14, 2010 - 11:07am
V1057 Cygni is a young stellar object known as a FUOR or FU Orionis variable. These stars are still in the process of forming, accreting gas from the clouds they formed from. FUORs undergo irregular episodes of brightening lasting for several years that are believed to be caused...
January 23, 2013 - 11:33am
If a nova reaches naked eye brightness, and nobody sees it, does it exist? Almost certainly.
While visiting AAVSO Headquarters in early February 2013, LSU's Brad Schaefer noted that since the Second World War, there has only been one nova to reach second magnitude, 1975'...
September 14, 2010 - 11:24am
The symbiotic nova V407 Cyg made news headlines in mid-2010 when the Fermi Gamma-Ray Satellite unexpectedly detected gamma rays from its most recent outburst. The nova was discovered in March of 2010, and has been followed by astronomers world-wide since then. Surprisingly, the...
December 11, 2012 - 12:23pm
V4334 Sgr, also known as Sakurai's Object, is a cousin to last week's LCOTW, FG Sagittae. The star was discovered by Y. Sakurai in 1996 as a possible nova in Sagittarius, but it soon became clear that this object wasn't an accreting white dwarf undergoing a thermonuclear...
August 23, 2012 - 10:54am
V455 Andromedae is a member of the WZ Sagittae subclass of dwarf novae. These are stars that undergo very infrequent dwarf nova outbursts with very large amplitudes. They have low masses and low accretion rates, and so in quiescence they're fainter than average dwarf nova...
April 7, 2011 - 3:42pm
V5558 Sgr, or Nova Sagittarii 2007, is a fascinating very slow nova that continues to decline nearly four years after outburst. After steadily rising for nearly a hundred days, the nova underwent a series of large-amplitude brightenings over the next two hundred days before beginning a...
July 30, 2012 - 10:30am
2012 is shaping up to be a very busy year for novae. As of July 30, we're up to five novae in Sagittarius alone! When it rains it pours.
The first nova in Sagittarius this season, V5589 Sgr, was a very fast nova, fading by three magnitudes in about...
August 3, 2012 - 11:54am
V705 Cas, or Nova Cas 1993, was a bright northern hemisphere nova that reached fifth magnitude. It belongs to the class of novae with dust dips starting shortly after maximum. The nova fades rapidly by as much as ten magnitudes before returning several magnitudes fainter than...
July 18, 2010 - 12:33pm
V838 Mon is one of the best examples of the light echo phenomenon. It was believed to be a nova at first -- Nova Mon 2002 -- but its subsequent photometric behavior shown in this light curve is unlike any typical nova. The subsequent light echo was observed propagating outwards...
February 7, 2011 - 12:38pm
Among bright novae, the name "V841 Oph" probably doesn't spring to mind immediately. That's probably because it went into outburst in 1848! This nova, discovered by the famed British observer J.R. Hind...
