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Matthew Templeton
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...

Matthew Templeton
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...

Matthew Templeton
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...

Matthew Templeton
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...

Matthew Templeton
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...

Matthew Templeton
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...

Matthew Templeton
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...

Matthew Templeton
October 21, 2010 - 6:02pm

V854 Cen is a fine R Coronae Borealis star for southern observers, reaching binocular brightness at maximum, but diving below 14th magnitude at minimum.  It entered the AAVSO observing program relatively recently (1986), but has been well-observed by southern observers since.  R CrB...

Matthew Templeton
October 22, 2010 - 9:18am

VW Hydri is a superb cataclysmic variable for southern observers, and belongs to the interesting subclass of dwarf novae known as SU Ursae Majoris stars, or UGSUs.  The UGSUs have two different kinds of outburst behaviors: normal outbursts lasting for a few days and...

Matthew Templeton
September 29, 2010 - 12:57pm

VX For is a southern member of the WZ Sge class of dwarf novae.  VX For went into outburst in mid-September 2009, remaining active for around 50 days.  Its outburst, like those of other WZ Sge stars, was characterized by a large amplitude, long-duration outburst of 7 magnitudes that...

Matthew Templeton
December 21, 2012 - 10:05am

What on Earth is going on with WW Cet?

This star had long been catalogued as a Z Camelopardalis (Z Cam)-type dwarf novae, despite not exhibiting one of the hallmarks of the Z Cam class, the standstill between outburst and quiescence.  Then within the past few years, it...

Matthew Templeton
January 22, 2013 - 4:09pm

WW Vulpeculae is a young stellar variable of the UXOR or UX Orionis class.  These stars are known to undergo sudden, random, and very dramatic drops in brightness of up to several magnitudes.  It's believed that the fades in the UXORs are caused by obscuration by some...

Matthew Templeton
September 14, 2010 - 2:14pm

WZ Sge is the prototype of an exceptional class of dwarf novae with large amplitudes, long recurrence times, low mass-transfer rates, and very short orbital periods.  They're cataclysmic variables consisting of a white dwarf and a low-mass companion object locked in close orbit about...

Matthew Templeton
November 7, 2012 - 10:56am

Y Lyncis is an interesting semiregular of the SRc (supergiant) subclass with an obvious long secondary period.  While it has a primary pulsation period just over 100 days, there's a longer (and larger) periodicity over 1000 days.  Such behavior is common among this class of...

Matthew Templeton
April 21, 2011 - 3:01pm

YY Herculis is the third of the symbiotics we're showing during our three-week series on this interesting class of stars.  YY Her shows symbiotic outbursts of more than two magnitudes lasting for hundreds of days, and recurring sporadically on timescales of thousands of days. ...

Matthew Templeton
February 8, 2011 - 4:46pm

YZ Cnc is one of the more popular of the SU Ursae Majoris subtype dwarf novae.  One of the defining characteristics of the SU UMa (or "UGSU") class is the occurrence of occasional superoutbursts that rise higher and last longer than normal outbursts that characterize all dwarf...

Matthew Templeton
November 13, 2011 - 3:23pm

Z Andromedae is the class prototype of the symbiotic stars, binary stars consisting of a red giant donor star and a hot accreting star, either a white dwarf or neutron star.  The most prominent features of the Z Andromedae light curve shown here are the outbursts that occur roughly every...

SXN
August 17, 2010 - 10:14am

Z CMa is a pre-main-sequence binary system composed of an embedded Herbig Be star, undergoing photometric outbursts, and a FU Orionis star. The Herbig Be component underwent the largest optical outburst in its recorded history in 2008, with another large outburst in early 2011. The origin of...

Matthew Templeton
April 22, 2011 - 12:25pm

This week's Light Curve of the Week is less about the star -- the eclipsing binary Z Draconis -- than it is about this particular observer, Ed Halbach.  Halbach was one of the most prolific of the AAVSO's 20th Century observers, sending us regular observations of hundreds of stars...

Matthew Templeton
October 8, 2010 - 3:04pm

Z Tauri is a Mira variable with a period of 466 days, and an amplitude of about four magnitudes... or so we thought!  In reality, Z Tau is a star with a nearby constant star within 10 arcseconds that most observers can't resolve.  When Z Tau goes into decline and falls below...

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