Zobrazeno 1 - 10
of 24
pro vyhledávání: '"Laurits Leedjärv"'
Autor:
Colin P. Folsom, Mihkel Kama, Tõnis Eenmäe, Indrek Kolka, Anna Aret, Vitalii Checha, Anni Kasikov, Laurits Leedjärv, Heleri Ramler
Context: Few exoplanets around hot stars with radiative envelopes have been discovered, although new observations from the TESS mission are improving this. Stars with radiative envelopes have little mixing at their surface, and thus their surface abu
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::8f9906cbab12d8cc42a951555361326f
http://arxiv.org/abs/2111.07526
http://arxiv.org/abs/2111.07526
Symbiotic stars are strongly interacting binaries, consisting of a white dwarf and a cool giant, mainly of spectral type M. AG Draconis belongs to a less numerous group of the yellow symbiotic systems, as the cool component in this binary is of a spe
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ec7169d98371f7066f23803f1f65ed61
http://arxiv.org/abs/2006.02982
http://arxiv.org/abs/2006.02982
The symbiotic binary AG Dra regularly undergoes quiescent and active stages which consist of several outbursts repeating with about 360d interval. The recent outburst activity of AG Dra started by the minor outburst in the late spring of 2015 and was
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::66edc82a17043cc222bc2be9654b7b03
http://arxiv.org/abs/1806.05935
http://arxiv.org/abs/1806.05935
Publikováno v:
Monthly Notices of the Royal Astronomical Society. 443:1103-1112
AG Dra is a well known bright symbiotic binary with a white dwarf and a pulsating red giant. The long-term photometry monitoring and a new behaviour of the system are presented. The detailed period analysis of photometry as well as spectroscopy was c
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::95365e2f87657f4572955c77b7924e16
https://doi.org/10.1093/mnras/stu1162
https://doi.org/10.1093/mnras/stu1162
Publikováno v:
EAS Publications Series. :103-105
The symbiotic system AG Dra regularly undergoes quiescent and active stages which consist of the series of individual outbursts. The period analysis of new and historical photometric data, as well as radial velocities, confirmed the presence of the t
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::e2b6bb7610d679aed12aacb4228a82d7
https://doi.org/10.1051/eas/1571020
https://doi.org/10.1051/eas/1571020
Publikováno v:
Open Astronomy, Vol 21, Iss 4, Pp 531-536 (2012)
Scopus-Elsevier
Scopus-Elsevier
We present V - and I-passband photometry of massive stars in the Cyg OB1 and Cyg OB2 associations, based on about 80 observing nights spanning 300 days in the 2011 season. The variability of 22 supergiants and 48 OB-stars with luminosity classes III-
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::628ac82ee15fba190360bae9b4fd0ccb
https://doaj.org/article/eb93ed8b92a84aa49296029241978245
https://doaj.org/article/eb93ed8b92a84aa49296029241978245
Autor:
Laurits Leedjärv
Publikováno v:
Proceedings of the International Astronomical Union. 5:528-532
History and present state of astronomy in a small North-Eastern European country are considered. There is a rather big number (about 35) of professional astronomers in Estonia, including 21 IAU members. Through some outstanding persons, astronomy in
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::ef9705555d79fe2cb64b762808576b61
https://doi.org/10.1017/s1743921311002791
https://doi.org/10.1017/s1743921311002791
Variations of the emission lines in the spectrum of the yellow symbiotic star AG Dra have been studied for over 14 years (1997 - 2011), using more than 500 spectra obtained on the 1.5-metre telescope at Tartu Observatory, Estonia. The time interval c
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::28617294787f689544a71023792a1ece
Autor:
T. Kipper, I. Kolka, K. Annuk, P. Skoda, Valentina G. Klochkova, Alar Puss, A. Hirv, M. Slechta, Laurits Leedjärv
Publikováno v:
Astronomy & Astrophysics. 416:1107-1115
Spectroscopic observations of the peculiar variable V838 Mon during the period from the second light outburst until the fast dimming are presented. We describe high resolution (R ≈ 60 000) high S /N spectra obtained a day before the second light ma
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::44c44b9f652a5029465662eb3b72a0fb
https://doi.org/10.1051/0004-6361:20031385
https://doi.org/10.1051/0004-6361:20031385
Publikováno v:
Astronomy & Astrophysics. 415:273-282
The halo symbiotic star AG Dra has been monitored spectroscopically at the Tartu Observatory, Estonia, from September 1997 to March 2003. Altogether 189 spectra are used in the present paper. In addition, photometric UBVri observations at the Piwnice
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::ef628b327b5c6edee35db8e89f61e53b
https://doi.org/10.1051/0004-6361:20034224
https://doi.org/10.1051/0004-6361:20034224