Some points of the monitoring of flare stars using the synchronous network of remote telescopes
We analyse the efficiency of observational campaigns which were carried out during seven years involving four astropoints in Ukraine, Russia, Greece, and Bulgaria. A possibility of the synchronous monitoring of stellar flares is discussed in this paper.
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Головна астрономічна обсерваторія НАН України
2005
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| Цитувати: | Some points of the monitoring of flare stars using the synchronous network of remote telescopes / Ya. Romanyuk // Кинематика и физика небесных тел. — 2005. — Т. 21, № 5-додаток. — С. 291-294. — Бібліогр.: 4 назв. — англ. |
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irk-123456789-796612015-04-04T03:02:28Z Some points of the monitoring of flare stars using the synchronous network of remote telescopes Romanyuk, Ya. MS3: Physics of Stars and Galaxies We analyse the efficiency of observational campaigns which were carried out during seven years involving four astropoints in Ukraine, Russia, Greece, and Bulgaria. A possibility of the synchronous monitoring of stellar flares is discussed in this paper. 2005 Article Some points of the monitoring of flare stars using the synchronous network of remote telescopes / Ya. Romanyuk // Кинематика и физика небесных тел. — 2005. — Т. 21, № 5-додаток. — С. 291-294. — Бібліогр.: 4 назв. — англ. 0233-7665 http://dspace.nbuv.gov.ua/handle/123456789/79661 en Кинематика и физика небесных тел Головна астрономічна обсерваторія НАН України |
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MS3: Physics of Stars and Galaxies MS3: Physics of Stars and Galaxies |
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MS3: Physics of Stars and Galaxies MS3: Physics of Stars and Galaxies Romanyuk, Ya. Some points of the monitoring of flare stars using the synchronous network of remote telescopes Кинематика и физика небесных тел |
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We analyse the efficiency of observational campaigns which were carried out during seven years involving four astropoints in Ukraine, Russia, Greece, and Bulgaria. A possibility of the synchronous monitoring of stellar flares is discussed in this paper. |
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Article |
| author |
Romanyuk, Ya. |
| author_facet |
Romanyuk, Ya. |
| author_sort |
Romanyuk, Ya. |
| title |
Some points of the monitoring of flare stars using the synchronous network of remote telescopes |
| title_short |
Some points of the monitoring of flare stars using the synchronous network of remote telescopes |
| title_full |
Some points of the monitoring of flare stars using the synchronous network of remote telescopes |
| title_fullStr |
Some points of the monitoring of flare stars using the synchronous network of remote telescopes |
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Some points of the monitoring of flare stars using the synchronous network of remote telescopes |
| title_sort |
some points of the monitoring of flare stars using the synchronous network of remote telescopes |
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Головна астрономічна обсерваторія НАН України |
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2005 |
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MS3: Physics of Stars and Galaxies |
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http://dspace.nbuv.gov.ua/handle/123456789/79661 |
| citation_txt |
Some points of the monitoring of flare stars using the synchronous network of remote telescopes / Ya. Romanyuk // Кинематика и физика небесных тел. — 2005. — Т. 21, № 5-додаток. — С. 291-294. — Бібліогр.: 4 назв. — англ. |
| series |
Кинематика и физика небесных тел |
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AT romanyukya somepointsofthemonitoringofflarestarsusingthesynchronousnetworkofremotetelescopes |
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2025-07-06T03:41:04Z |
| last_indexed |
2025-07-06T03:41:04Z |
| _version_ |
1836867403199283200 |
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SOME POINTS OF THE MONITORING OF FLARE STARS
USING THE SYNCHRONOUS NETWORK OF REMOTE TELESCOPES
Ya. Romanyuk
Main Astronomical Observatory, NAS of Ukraine
27 Akademika Zabolotnoho Str., 03680 Kyiv, Ukraine
e-mail: romanyuk@mao.kiev.ua
We analyse the efficiency of observational campaigns which were carried out during seven years in-
volving four astropoints in Ukraine, Russia, Greece, and Bulgaria. A possibility of the synchronous
monitoring of stellar flares is discussed in this paper.
INTRODUCTION
The Synchronous Network of Remote Telescopes (SNT) [3] started as a coordinated network of telescopes in
1997, when the 50-inch telescope at the Crimean Astrophysical Observatory was equipped with the second
High Speed Two Channel Photometer [4]. The SNT activities are supporting by five groups of astronomers
which are working at the Crimean Astrophysical Observatory (CrAO, Ukraine), in the International Center for
Astronomical, Medical and Ecological Research (Ukraine–Russia), at the Aristoteleon University (Greece), in
the Institute of Astronomy of the Bulgarian Academy of Sciences and at the Main Astronomical Observatory
of the National Academy of Sciences of Ukraine. They use photometric complexes at the Terskol Observatory
(the Northern Caucasus), CrAO, the Stephanion Observatory (Greece), the Belogradchik Observatory, and/or
the Rozhen Observatory (Bulgaria). Three sets of photometers are able to synchronize their time clocks to
the UTC with an accuracy up to 1 μs using GPS antennas Acutime 2000.
The primary focus of the SNT is the synchronous monitoring of UV Ceti type stars [2] with high speed (about
10–100 ms per count). Hereby, the data obtained synchronously at distant observatories promote the getting
new results in the study of flare-related phenomena in stars. In the previous years simultaneous observations
of stars EV Lac, AD Leo, BY Dra, YZ Cmi, KR Aur, etc. were performed.
The greatest attention was paid to synchronous observations of the flare star EV Lac with the use of two,
three, four, and five photometers at four observatories. A short statistic analysis of the results obtained in
1998–2003 is presented below.
OBSERVATIONS AND RESULTS
A complete and detailed review of the first coordinated international observations with the SNT in September
1998 was prepared by Alekseev et al. [1]. Five telescopes at four observatories registered 18 flares. Ten of them
were observed simultaneously at two observatories, five – at three observatories, and one – at four observatories.
Some observations in the IR region as well spectra were obtained too. The whole campaign was carried out
during seven nights with the observing time planned as six hours for each night.
In August 1999 observations were carried out at the Terskol Observatory and the Stephanion Observatory.
The observing time was planned as four hours for each night. Two telescopes registered 23 flares during 12 nights
but there was not flare observed simultaneously at two astrosites because the bad weather conditions.
The total coverage of EV Lac with observations achieved during the international campaigns in 2000–2003
is showed in Tables 1–5. They present our observations for each night using three terms:
• Synchronous time of monitoring at piece of astrosites (ST#S).
• Number of flares registered simultaneously at piece of astrosites (FR#S).
• Rate of synchronous time at piece of astrosites (RST#S).
The international campaign in October 2000 (Table 1) was not enough successful, because it was too cloudy
at observational sites during the observational period. The high-speed two-channel photometer of the 50-inch
telescope of the Crimean Astrophysical Observatory was in non-operational state, therefore many sets of the data
c© Ya. Romanyuk, 2004
291
were unassured. Five telescopes at four observatories have registered 21 flares during 10 nights with the planned
observing time of six hours per night, but there were only two flares observed simultaneously with two telescopes.
Table 1. Observations of EV Lacertae in October 2000
Date ST2S ST3S ST4S FR1S FR2S FR3S FR4S RST2S RST3S RST4S
21/22.10.2000 0 0 0 1 0 0 0 0 0 0
22/23.10.2000 4h37m 1h33m 0 2 0 0 0 77% 26% 0
23/24.10.2000 4h45m 0 0 0 0 0 0 79% 0 0
24/25.10.2000 5h45m 4h43m 2h44m 4 0 1 0 96% 77% 46%
25/26.10.2000 3h55m 0h37m 0 1 0 0 0 65% 10% 0
26/27.10.2000 5h17m 0 0 6 0 1 0 88% 0 0
27/28.10.2000 3h00m 2h15m 0 5 0 0 0 50% 38% 0
29/30.10.2000 2h54m 1h19m 0 2 0 0 0 48% 22% 0
30/31.10.2000 3h28m 0 0 0 0 0 0 58% 0 0
Two observational campaigns were organized in 2001: the first one was carried out during 9 nights in
September and the second – during 11 nights in October. For the September campaign (Table 2) we had
possibilities for the synchronous monitoring from two astrosites during five nights (five hours per night were
planned), but only during 2.2 hours of one night it was possible to observe simultaneously from three sites.
Three telescopes at three observatories have registered 19 flares, but no flare was observed at least with two
telescopes.
Table 2. Observations of EV Lacertae in September 2001
Date ST2S ST3S FR1S FR2S FR3S RST2S RST3S
09/10.09.2001 0 0 0 0 0 0 0
10/11.09.2001 0 0 1 0 0 0 0
11/12.09.2001 0 0 6 0 0 0 0
12/13.09.2001 0h13m 0 3 0 0 5% 0
13/14.09.2001 1h30m 0 0 0 0 34% 0
14/15.09.2001 3h57m 2h10m 3 0 0 79% 44%
15/16.09.2001 2h33m 0 0 0 0 58% 0
16/17.09.2001 0 0 2 0 0 0 0
17/18.10.2001 3h01m 0 4 0 0 64% 0
The weather conditions during the campaign on October 8–18, 2001 (Table 3) were bad at two of three
observatories. Only one of four flares was synchronously registered at two astrosites.
Table 3. Observations of EV Lacertae in October 2001
Date ST2S ST3S FR1S FR2S FR3S RST2S RST3S
08/09.10.2001 0 0 0 0 0 0 0
09/10.10.2001 0 0 0 0 0 0 0
10/11.10.2001 2h07m 0 0 0 0 0 0
11/12.10.2001 2h45m 0 0 0 0 0 0
12/13.10.2001 0 0 0 0 0 0 0
13/14.10.2001 1h23m 0 1 0 0 0 0
14/15.10.2001 2h15m 0 2 1 0 0 0
15/16.10.2001 20 0 0 0 0 0 0
16/17.10.2001 0 0 0 0 0 0 0
17/18.10.2001 0 0 1 0 0 0 0
18/19.10.2001 0 0 0 0 0 0 0
292
The 2002 international campaign for the monitoring the red dwarf EV Lac (Table 4) was carried out during
11 nights (five hours per night were planned). Four telescopes at three observatories were involved. They
registered 13 flares and three of them were simultaneously observed at two astrosites. The weather conditions
were bad in the Crimea and in the Northern Caucasus.
Table 4. Observations of EV Lacertae in October 2002
Date ST2S ST3S FR1S FR2S FR3S RST2S RST3S
01/02.10.2002 0 0 1 0 0 0 0
03/04.10.2002 2h00m 0 1 0 0 45% 0
04/05.10.2002 1h49m 0 2 0 0 39% 0
05/06.10.2002 0 0 0 0 0 0 0
08/09.10.2002 2h16m 0 2 0 0 45% 0
09/10.10.2002 3h35m 1h05m 1 1 0 66% 20%
10/11.10.2002 3h42m 0 3 2 0 100% 0
11/12.10.2002 0 0 3 0 0 0 0
The last international campaign for the monitoring EV Lac was carried out from September 23 to Octo-
ber 4, 2003 (Table 5). The planned time for monitoring was 4 hours per night. In spite of the inability of
the 2-m telescope of the Terskol Observatory, it was the most successful period for the synchronous observa-
tions the target star from two observatories. Four telescopes at three observatories registered 26 flares. 13 of
them were synchronously observed at the Crimean Astrophysical Observatory and the Stephanion Observatory
and one was registered with all four telescopes.
Table 5. Observations of EV Lacertae in October 2003
Date ST2S ST3S FR1S FR2S FR3S RST2S RST3S
23/24.09.2003 3h11m 2h49m 0 0 0 80% 70%
24/25.09.2003 3h47m 0 4 3 0 86% 0
25/26.09.2003 4h10m 0 1 1 0 81% 0
26/27.09.2003 0h30m 0 3 0 0 12% 0
27/28.09.2003 2h32m 2h27m 2 1 1 70% 68%
28/29.09.2003 1h48m 0 5 2 0 42% 0
29/30.09.2003 0 0 3 0 0 0 0
30/01.10.2003 4h15m 0 3 2 0 99% 0
01/02.10.2003 3h21m 0 2 0 0 80% 0
02/03.10.2003 3h52m 0 3 2 0 74% 0
03/04.10.2003 0 0 0 0 0 0 0
CONCLUSIONS
The observations statistics of the five international campaigns carried out in 2000–2003 are presented in
Tables 1–5. At least three of four observatories from Russia (Terskol), Ukraine (CrAO), Greece (Stephanion),
and Bulgaria (Rozhen or Belogradchik) were involved in each campaign. In the monitoring campaign 2000
all four observatories with five telescopes have participated, in campaigns in 2001–2003 – three observato-
ries. 241 hours during 53 nights were planned for synchronous observations during all campaigns. We ob-
tained 97 (40%) hours of synchronous observations at two astrosites and about 19 hours – at three astrosites.
20 flares were synchronously registered with photometers at two sites and only one – with photometers at three
sites. We have not any minute of synchronous observations at four sites during possible 60 hours (10 nights) in
2000. The good common statistics for the data obtained simultaneously at two astropoints do not satisfy us.
There are some reasons of the non-coincidence of observational tine intervals periods at the participated
observatories. The main one is a weather factor, the next – operational integrity and possibility to get observa-
tional time on fixed dates on the telescopes. Sometime distant telescopes use different time intervals to measure
the sky background or reference stars for the same observational set. This makes impossible to register some
flares simultaneously at least with two photometers.
293
We hope this information will be useful for astronomers who plan synchronous observations of such rare
phenomena as flares on UV Ceti stars [2] or similar.
Acknowledgements. I am grateful to B. Zhilyaev, I. Verlyuk, J. Seiradakis, S. Avgoloupis, M. Contadakis,
R. Konstantinova-Antova, and A. Antov for the help in the collection of all obtained observational data, and to
V. Godunova for her useful remarks.
Observations of the Kyiv team at the Crimean Astrophysical Observatory and at the Terskol Observatory
during 2000–2003 were mostly supported by grants of the Ministry of the Education and Science of Ukraine
2M/146–2000 and 2M/86–2001.
[1] Alekseev I. Yu., Antov A. P., Avgoloupis S. J., et al. Coordinated observations of the red dwarf flare star EV Lac
in 1998 // Kinematics and Physics of Celestial Bodies.–2001.–17, N 2.–P. 147–156.
[2] Gershberg R. E. The solar-type activity amongst the main sequence stars.–Odessa: Astroprint, 2002.–688 p.
[3] Romanyuk Ya., Zhilyaev B., Svyatogorov O., et al. The synchronous network of optical telescopes: a new in-
strument for stellar photometry // Proc. of 5th Conf. of the Hellenic Astron. Soc. Crete, Sept. 20–22, 2001.
[http://www.astro.auth.gr/∼helasmtg/2001].
[4] Zhilyaev B. E., Romanyuk Ya. O., Svyatogorov O. A. The high-speed automatic two-channel photometer // Astron.
Zh.–1992.–69, N 4.–P. 895–900.
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