Variable Stars / Stellar photometry

Lajatico astronomical observatory has got photometric U B V R I filters for variable star observations. It’s possible to write a proposal for photometric observations, or write a mail to info@astronomicalcentre.org.

The observations can be done in remote control, in service by observatory staff, in observatory control room.

Some pubblication about variable stars studies in the old observatory site.

Mariinsjaya High School, Odessa Ukraine

Odessa National Martime University, Odessa Ukraine

Authors

M.Mogoryan, Natalia Virnina & Fabio Martinelli

Seven New Variables at the Borderline of Pegasus and Lacerta!

One year of work, one year of observation with telescope Meade 10″ focal lenth 1600 DTA cameras with ccd sensor KAF1600

1° variable stare, type EA, coordinates: 22 46 57.72, +34 05 55.2

Image:

Light curve

1. Secondary minimum: HJD = 2456536.8522.O’Connell effect (O’Connell 1951) is possible. Alternative period is 0d.5549. MinII = 13m.649.

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2° variable star, type EW, coordinates: 22 47 08.02, +34 14 21.6

Light curve

2. Secondary minimum: HJD = 2456534.8598. MinII = 17m.10

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3° variable star, type EW, coordinates: 22 47 17.68, +34 06 37.2

Light curve

3. Secondary minimum: HJD = 2456535.8633. MinII = 15m.18.

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4° Variable star, type EW, coordinates:  22 48 27.69, +34 13 50.9

 

 

 

Light curve

 

 

4. Secondary minima:
HJD = 2456534.8861,
HJD = 2456535.8497,
HJD = 2456536.8155.
MinII = 15m.13. Variable O’Connell effect is possible. Also there is a flat part on the phase curve in the secondary minimum.

 

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5° Variable star, type EA, coordinates: 22 48 34.85, +34 15 22.0

 

 

 

Light curve

 

5. Secondary minima: HJD = 2456159.6101, HJD = 2456224.3904, HJD = 2456559.5520.

The phase curve is combined of unfiltered observations, collected in 2012 with Mead 10″ (black points); R-filtered observations obtained in 2013 with the same telescope (blue points); and R-filtered observations, made with the T5 telescope of the iTelescope.net observatory (red points).

 

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6° Variable star, type, EB, coordinates: 22 49 47.54, +34 00 55.8

 

 

 

Light curve

 

 

 

6. Primary minima: HJD = 2456535.9370, HJD = 2456542.7177. MinII = 14m.32. O’Connell effect is clearly present. A total eclipse in the primary minimum is possible. The orbital inclination is close to 90°. Another interesting feature is a rather large difference in minima depths: minI – minII = 0m.28. Despite the shape of the light curve and the period, which are typical of EW-type binaries, the components of this binary do not show thermal contact.

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7° Variable star type, EW, coordinates: 22 50 10.69, +34 04 56.3

 

 

 

 

Light curve

7. MinII = 14m.97.

 

Full articles:  http://www.astronet.ru/db/varstars/msg/1297456

 

 

Discovered a new variable star in Pegasus

 

Scoperta una nuova Variabile in Pegaso Grazie alla collaborazione tra astrofili è stata scoperta la variazione di luminosità di una stella nella costellazione del Pegaso. La notte del 07/08/2013 dall ‘osservatorio 104 San Marcello Pistoiese veniva effettuata una sessione osservativa al fine di determinare il periodo di rotazione dell’asteroide 2013 PS10.. Le immagini acquisite, che hanno un FOV di 34′x34′, con una risoluzione di 2″/pixel, venivano trasmesse a Lorenzo Franco  A81 Balzaretto observatory che individuava due nuovi probabili variabili nel campo ripreso. Al fine di accertare l’effettiva variabilità delle due stelle, una delle quali già censita nel catalogo VSX  The International Variable Star Index, era necessario effettuare ulteriori serate osservative. Grazie alla disponibilità e collaborazione di Fabio Martinelli dell’osservatorio Montecatini Val di Cecina   Astronomical Center, venivano effettuate nelle notti del 16 e 17 agosto ulteriori  sessioni osservative utilizzando il telescopio  Schmidt Cassegrain 0.25-m. I dati raccolti venivano inviati a Lorenzo Franco, che determinava il periodo di variabilità  in 0.314d della stella di 15.82 mag.  c0n un ampiezza di 0.55 mag catalogata UCAC4 567-122720. La scoperta della nuova stella variabile di tipo EW (W-Uma), variabile ad eclisse le cui componenti sono praticamente a contatto tra loro,  è stata censita nell’archivio del VSX .

 

 

 

 

Light Curve  

 

 

 

 

 

 

 

Di seguito nell’ immagine ottenuta da San Marcello di evidenzia la nuova stella variabile.

 

 

 

 

 

 

 

 

Link AAVSO:  http://www.aavso.org/vsx/index.php?view=detail.top&oid=322866 New variable star in Peg Paolo Bacci, Lorenzo Franco, Fabio Martinelli

 

 

 

 

 

 

Discovery of EW variable star in Lyra by Astronomicalcentre.

 

 

 

Discovered of EW variable star in Lyra during the observations of others astronomical targets by Telescope SC 35 cm diameter with CCD

 

 

camera SBIG KAF1600. After several nights of observations we have the full period of this variable star. Observations in collaboration with Denis Denisenko, Researcher by, High Energy Astrophysics Department, Russian Space Research Institute. Observation Author: Fabio Martinelli, responsable for Astronomical centre. Data redution, and elaboration by Giorgio Corfini,

 

Astronomicalcentre Staff.

 

 

 

 

 

 

 

 

AAVSO comunication: http://www.aavso.org/vsx/index.php?view=detail.top&oid=297572Thanks to every amateur astronomer and astronomer for every resoult of Astronomicalcentre. Observatory Members.

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Peremennye Zvezdy

(Variable Stars) 32

, No. 3, 2012

Received 26 July; accepted 14 August.

A Study of the Cataclysmic Variable 1RXS J174320.1{042953

D. V. Denisenko & F. Martinelli

Sternberg Astronomical Institute at Lomonosov Moscow State University, Russia;

e-mail: d.v.denisenko@gmail.com

Montecatini val di Cecina astronomicalcentre:

info@astronomicalcentre.org

http://images.astronet.ru/pubd/2012/08/15/0001269032/pz-32-003.pdf

    http://arxiv.org/abs/1207.6320

 

[vsnet-alert 13737] 1RXS J231935.0+364705: superhumps evolution

Denis Denisenko

d.v.denisenko at gmail.com

Fri Oct 7 17:55:49 JST 2011 Fabio Martinelli (Astronomical Centre at Montecatini, Italy) has obtained fifty 160-sec exposures of J2319+3647 covering 2.3 hours interval from 00:58 to 03:18 UT on 2011 Oct. 05. Light curve (unfiltered magnitudes with Red zero point) is uploaded to

http://pics.livejournal.com/bigdenru/pic/000adk0k/

I was using R=14.4 as the comparison star and R=14.2 as check star from my 2007 finder chart at http://hea.iki.rssi.ru/~denis/J2319+3647-comps.gif

 

Amplitude of orbital modualtion has decreased to 0.13-0.14m. It was 0.24m during Oct. 01/02 observations by Etienne Morelle. Denis Denisenko P.S. Regarding the new object from vsnet-alert 13736: dwarf nova 1RXS J231935.0+364705 is also a hard ROSAT source (HR1=1.00+/-0.09, HR2=0.47+/-0.16).

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