J/AJ/140/483 Flares of UV Cet type stars (Dal+, 2010)
A new method for classifying flares of UV Ceti type stars:
differences between slow and fast flares.
Dal H.A., Evren S.
<Astron. J., 140, 483-489 (2010)>
=2010AJ....140..483D 2010AJ....140..483D
ADC_Keywords: Stars, variable ; Photometry
Keywords: methods: data analysis - methods: statistical - stars: flare -
stars: individual (AD Leo, EV Lac, EQ Peg, V1054 Oph)
Abstract:
In this study, a new method is presented to classify flares derived
from the photoelectric photometry of UV Ceti type stars. This method
is based on statistical analyses using an independent samples t-test.
The data used in analyses were obtained from four flare stars observed
between 2004 and 2007. The total number of flares obtained in the
observations of AD Leo, EV Lac, EQ Peg, and V1054 Oph is 321 in the
standard Johnson U band. As a result flares can be separated into two
types, slow and fast, depending on the ratio of flare decay time to
flare rise time. The ratio is below 3.5 for all slow flares, while it
is above 3.5 for all fast flares. Also, according to the independent
samples t-test, there is a difference of about 157 s between
equivalent durations of slow and fast flares. In addition, there are
significant differences between amplitudes and rise times of slow and
fast flares.
Description:
The observations were acquired with a High-speed Three Channel
Photometer attached to a 48cm Cassegrain-type telescope in the Ege
University Observatory between 2004 and 2006.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
stars.dat 68 4 Basic parameters for the targets studied
table3.dat 80 321 Parameters computed from observed flares
fits/* . 4 Time series observations, as FITS files
corresponding to the figures of the paper
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Byte-by-byte Description of file: stars.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Name Star name
11- 12 I2 h RAh Right ascension (J2000)
14- 15 I2 min RAm Right ascension (J2000)
17- 21 F5.2 s RAs Right ascension (J2000)
23 A1 --- DE- Declination sign (J2000)
24- 25 I2 deg DEd Declination (J2000)
27- 28 I2 arcmin DEm Declination (J2000)
30- 33 F4.1 arcsec DEs Declination (J2000)
35- 40 F6.3 mag Vmag V magnitude
42- 46 F5.3 mag B-V B-V colour index
48- 52 A5 --- SpType MK spectral type
54- 57 F4.2 pc Dist Distance
59- 63 F5.2 [Lsun] logLbol Bolometric luminosity
65- 68 A4 --- File [fig1-4] figure ID, in "fits" subdirectory
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Name Star name
11- 20 A10 "DD/MM/YYYY" Obs.Date Date of Observation
22- 34 F13.5 d HJD Heliocentric Julian date of flare
maximum moment
36- 39 I4 s TTime Total flare time
41- 44 I4 s DTime Flare decay time
46- 54 F9.4 s Dur Equivalent duration
56- 65 E10.4 10-7J Energy Flare energy
67- 71 F5.3 mag Umag Flare amplitude in U band
73- 76 A4 --- Type [Slow Fast] Flare type ("Slow" or "Fast")
78- 80 A3 --- Used [Yes No] Used in analysis ?
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 15-Jun-2012