The VVV Templates Project
손정주 (한국교원대학교)
전영범, 성현일 (KASI)
한장희, 이종택 (한국교원대학교)
Richard de Grijs (Kavli Institute for Astronomy & Astrophysics)
Rodolfo Angeloni (la Pontificia Universidad Catolica(PUC) -Chile)
2014 SURVEY SCIENCE GROUP WORKSHOP
VVV Project

The Vista Variables in the Vía Láctea (VVV) ESO Public Survey

ESO's Visible and Infrared Survey Telescope for Astronomy

4 m telescope

a wide near-infrared (IR) camera (VIRCAM)

a mosaic of 16 2048x2048 detectors

0.8-2.5 micron

an average pixel scale of 0.34"/pixel

FoV : 1.1x1.5 square degrees

1 magnitudes deeper than their 2MASS counterparts

provide a window into time-variable phenomena

a time span of about 5 years, with a total of 1929 hours of observing time
VVV Project
order 109 point sources within a total sky area of
520 deg2 will be monitored.
 The surveyed region includes 36 globular clusters and
about 314 known open clusters.
 A deep IR atlas in 5 passbands and a catalogue containing
an estimated 106 variable stars.
 Of
Light Curve Templates in the Near-IR: Towards Automated
Classification of VVV Light Curves for Cataclysmic Variable Stars

Cataclysmic Variables have been extensively observed at optical, ultraviolet, and X-ray
wavelengths, where their white dwarf primary stars and bright accretion disks dominate the spectral
energy distribution. Unfortunately, little is known about their infrared properties. The assumption that
infrared observations would reveal only the “uninteresting” secondary star has been shown to be
false, as recent investigations have instead shown.

A shorter time-scale it will provide a unique chance of enlarging our specific knowledge of the
cataclysmic phenomenon. In particular, time-series of NIR photometry would allow us to measure the
ellipsoidal variations of the tidally distorted mass-donor star as well as irradiation effects. By
modeling the modulation, we could then put strong constraints on fundamental parameters such as
the geometry of the binary, and, in case of the contribution of the mass-donor star in two or more
bands is known, it is possible to infer its spectral type (and surface temperature) and to estimate the
distance to the binary via photometric parallax.
Light Curve Templates in the Near-IR: Towards Automated
Classification of VVV Light Curves for Cataclysmic Variable Stars

Unlike previous variability surveys, such as MACHO and OGLE, the VVV Survey will
be carried out in the near-IR, mainly in the K band. While this will allow us to probe
deeper into the heavily obscured regions of the Galactic bulge and plane than ever
before, it also presents us with important challenges. In particular, the extensive,
high-quality templates that are needed for automated variable star classification
algorithms are not available in the near-IR. We have thus to build a large database
of well-defined, high-quality, near-IR light curves for variable stars of different types,
which will form the basis for the VVV automated classification.
This database will be critical for the successful outcome of the VVV Survey.
Light Curve Templates in the Near-IR: Towards Automated
Classification of VVV Light Curves for Cataclysmic Variable Stars

In order to properly classify as a template, a light curve must
meet some minimum observational criteria

first, the observations must be very precise, with the relative
error in the photometry being less than about 1/10 of the light
curve amplitude.

Second, the light curve itself must be complete, without any clear
gaps. This is of great importance to properly compute accurate
Fourier decomposition parameters for the light curves, as
needed in order to feed the automated classification algorithms.
Jones et al. (1996)
VVV Templates Project
SCIENTIFIC GOALS

The main goal is to derive well-defined light curve templates in
the near-IR for the automated classification of VVV light curves.
RR Lyrae stars in the globular cluster ω Centauri (Del Principe et al. 2006).
VVV Templates Project

Targets
#
Name
α (J2000)
δ (J2000)
K mag. P[d] Var. type
-------------------------------------------------------------------------------------------------01) V Sge
20 20 14.69 +21 06 10.39 9.811 0.5142 Novalike, Supersoft X-ray source
02) AE Aqr
20 40 09.16 -00 52 15.07
8.780 0.4151 Intermediate Polar
02) UU Aqr
22 09 05.76 -03 46 17.70 12.483 0.1636 SW Sex star
03) FO Aqr
22 17 55.38 -08 21 03.90 12.508 0.2018 Intermediate Polar
04) AO Psc
22 55 17.99 -03 10 40.00 13.088 0.1496 Intermediate Polar
05) IP Peg
23 23 08.55 +18 24 59.30 11.721 0.1582 Dwarf Novae
06) RX And
01 04 35.54 +41 17 57.80 11.56 0.2099 Z Cam star
07) HT Cas
01 10 13.13 +60 04 35.40 13.84
0.0736 SU UMa star
08) AY Psc
01 36 55.45 +07 16 29.30 14.002 0.0993 Nova-like, RW Tri star
09) RW Tri
02 25 36.15 +28 05 50.90 11.46
0.2319 Nova-like variable
10) GK Per
03 31 11.82 +43 54 16.80
~13
1.9968 Intermediate Polar, Fast Novae
11) V1309 Ori 05 15 41.41 +01 04 40.50 13.512 0.3326 polar/AM Her system
12) U Gem
07 55 05.24 +22 00 05.10 10.83 0.1769 SS Cyg star
13) SU UMa 08 12 28.26 +62 36 22.50 11.670 0.0076 Prototype of the SU UMa stars
14) Z Cam
08 25 13.20 +73 06 39.23 10.856 0.2898 Prototype of the Z Cam stars
15) GY Cnc
09 09 50.55 +18 49 47.50 13.118 0.1754 SS Cyg star
Telescopes
Europe

Italy - Osservatorio Astronomico di Padova (INAF-OAPd)
92cm Telescope, delta Scuti, SX Phe

Spain - Instituto de Astrofísica de Canarias (IAC)
1.52m, CAIN III, delta Scuti, SX Phe
Telescopes
Africa
 IRSF
Telescope : 1.4m, RR Lyrae in globular clusters (M62, NGC1851),
delta Scuti in open clusters (NGC6134)

0.75-m Telescope : delta Scuti, SX Phe, Ellipsoidal, Eclipsing binaries
Telescopes
North America

Canada
 Maxico : 2.12 m, CANICA
beta Cephei and delta Scuti
South America

Chile
Asia

Kazakshutan
 South Korea : 1.8 m BOAO
Bohyunsan Optical Astronomy Observatory (BOAO)
KASINICS
(KASI Near Infrared Camera
System)
- cooling temperature : sensor part =
30K
- temperature of cold box < 80K
- Pixel scale : 0.39" x 0.39"
- Field of view : 3.3' x 3.3'
- Gain(e-/ADU) : 2.56
- Readout Noise : 39 electrons
- Dark Current : 18.2 electrons/sec
- Average Seeing(BOAO) : 1.5" ~ 1.7"
- Filter : total 6 (J, H, Ks, L, H2, H3+)
Light Curve of BL Cam
: The Preliminary result of VVV light curve templates
BL Cam, 2MASS
R.A. (J2000) 03h 47m 19.8s
Dec. (J2000) +63°22’43”
Brightness <V> ~ 13.1mag
Period [d/h] 0.03909/0.93834
- Low metallicity ([Fe/H]=-2.4)
- High amplitude
- Short period and multi - periodicity
- One of well known 12 field SX Phe
star
Light Curve of IP Peg
: The Preliminary result of VVV light curve templates
α(J2000) : 23 23 08.55,
δ(J2000) : +18 24 59.30
K mag : 11.721,
P[d/h] : 0.1582/3.7968
dwarf nova - U Gem type
동반성에서 백색왜성을 둘러싸고 있는 강착원반으로
물질 유입이 이루어지고 있는 천체.불규칙한 주기의
outburst – 가시광에서 2등급 정도 밝아지는 것으로
알려져 있음.
Inclination : 80° ～ 85°
Mass ratio (q)=0.42
Distance = 115±30 pc to the system
Light Curve of CVs
: The Preliminary result of VVV light curve templates
Name
IPPeg
RW Tri
UU Aqr
BL Cam
V1007Cas
V2416Cyg
AY Psc
KV Per
RX And
V460And
AM Her
V1047 Her
BO Lyn
period(d/h)
0.1582/3.7968
0.2319/5.5656
0.1636/3.9264
0.03909/0.93834
0.0332/7.968
0.05589/1.34136
0.0993/2.3832
0.2491/5.9784
0.2099/5.0376
0.0749808/1.8
0.1289/3.0936
0.3207/7.6968
0.0934 / 2.2416
observation time
19:20 – 2:30
20:30 – 5:00
19:20 – 00:20
20:30 – 5:00
19:20 – 4:40
19:20 – 1:00
20:30 – 4:30
19:20 – 5:00
19:20 – 5:00
20:00 – 5:00
19:20 – 23:00
2:30 – 5:00
19:20-21:00
data
8h관측(2주기)
7h관측(1.3주기)
5h 관측(1.2주)
5h 관측(5주기)
9h 관측(1.1주기)
7h 관측(5.3주기)
8h 관측(1.3주기)
2h 관측(0.4주기)
9h 관측(5주기)
24h 관측(3주기)
36h 관측(16주기)
Thank you!