A search for clustering around Herbig Ae/Be stars

Testi, L.; Palla, F.; Natta, A.

doi:10.1051/aas:1998451

Cited by 173 publications

(291 citation statements)

References 45 publications

Supporting

Mentioning

270

Contrasting

Order By: Relevance

“…2), one of which is the Herbig AeBe star. This double source is accompanied by a small cluster of at least 10 fainter stars which are distributed in a region of ∼30 , in good agreement with Testi et al (1998). Only the most prominent stars in the central region have been labeled.…”

Section: Young Stars In the Regionsupporting

confidence: 79%

“…Thé et al 1994). The systematic searches for clustering around HAeBe stars carried out by Testi et al (1997Testi et al ( , 1998Testi et al ( , 1999) revealed a clear enhancement in the stellar surface density profile toward the central RNO 6 position; it appears that the central B star is accompanied by a small group of less luminous stars.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Cometary molecular clouds around RNO 6

Bachiller

Fuente

Kumar

2002

A&A

View full text Add to dashboard Cite

Abstract. We present molecular line observations of the star-forming cloud around RNO 6 along with a newly discovered nearby molecular cloud that we name RNO 6 NW. Both clouds display striking similarities in their cometary structures and overall kinematics. By using 13 CO line observations, we estimate that these clouds have similar sizes (∼4.5 pc) and masses (∼200 M ). Both molecular clouds RNO 6 and RNO 6 NW are active in star formation. From new high resolution near-IR narrowband images, we confirm that RNO 6 hosts an embedded IR cluster that includes a Herbig Be star. A conspicuous H2 filament is found to delineate the dense cometary head of the globule. RNO 6 NW hosts at least two IR sources and a bipolar molecular outflow of ∼0.9 pc of length and ∼0.5 M of mass. We show that the cometary structure of both clouds has been created by the UV radiation from numerous OB stars lying ∼1.5 • to the north. Such OB stars are associated with the double cluster h and χ Persei, and are probably members of the Per OB1 association. Thus star formation inside these clouds has been very likely triggered by the Radiation Driven Implosion (RDI) mechanism. From comparison to RDI theoretical models, we find that the similar kinematics and morphology of both clouds is well explained if they are at a re-expansion phase. Triggered sequential star formation also explains the observed spatial distribution of the members of the near-IR cluster inside the RNO 6 cloud, and the morphology of the H2 filament. We conclude that the RNO 6 and RNO 6 NW clouds are high-mass counterparts to the cometary globules of smaller masses which have been studied up to now. Thus our observations demonstrate that the RDI mechanism can produce, not only low mass stars in small globules, but also intermediate mass stars and clusters in massive clouds.

show abstract

Section: Young Stars In the Regionsupporting

confidence: 79%

Section: Introductionmentioning

confidence: 99%

Cometary molecular clouds around RNO 6

Bachiller

Fuente

Kumar

2002

A&A

View full text Add to dashboard Cite

show abstract

“…This star has since been classified as a B1-B5 V star (van den Ancker, de Winter, & Tjin A Djie 1998; Testi, Palla, & Natta 1999) with an age of 5 Â 10 4 yr (Testi, Palla, & Natta 1998). Its distance has been estimated as 800 pc based on distances for NGC 2247 (Racine 1968;Herbst et al 1982).…”

Section: Hd 259431mentioning

confidence: 99%

The Dusty Circumstellar Environments of A[CLC]e[/CLC]/B[CLC]e[/CLC] Protoplanetary Disk Candidates

Polomski

Telesco

Piña

et al. 2002

The Astronomical Journal

View full text Add to dashboard Cite

We have obtained high spatial resolution mid-IR observations of four intermediate-mass pre-mainsequence stars: HD 259431, AS 310, LkH 234, and MWC 1080. Our observations reveal the morphology of the circumstellar (500-10,000 AU) environments of these young stars. We resolve companion stars and complex diffuse emission from dust that can account for on average 50% of the IR emission detected in previous low-resolution observations. We calculate new spectral indices for these objects and show that they differ from those expected from simple geometrically flat disk models. We also show mid-IR spectral energy distributions that reveal the presence of silicate emission and absorption features for several objects. Finally, temperature maps constructed from our observations suggest the presence of transiently heated grains, and optical depth maps point to the locations of the most embedded objects.

show abstract

“…In x 2 of the paper we describe our sample. Spectroscopic observations obtained are presented in Baines et al 2004;(18) Malfait et al 1998;(19) Acke et al 2005;(20) Testi et al 1998;(21) van den Ancker et al 2004;(22) Corcoran & Ray 1998;(23) Miroshnichenko et al 2001b;(24) Alencar et al 2003;(25) Hamaguchi et al 2005;(26) Terranegra et al 1994;(27) van den Ancker et al 1998;(28) Berrilli et al 1992;(29) Perryman et al 1997;(30) Calvet et al 2004;(31) Leinert et al 1997;(32) Kawamura et al 1998;(33) Hernández et al 2005;(34) Herbst & Racine 1976;(35) Herbst et al 1982;(36) Shevchenko et al 1999;(37) Leinert et al 2004;(38) Eisner et al 2004;(39) Shevchenko & Yakubov 1989. x 3. Main results of our study are presented in x 4 and discussed in detail in x 5.…”

Section: Introductionmentioning

confidence: 99%

Evolution of Emission‐Line Activity in Intermediate‐Mass Young Stars

Manoj

Bhatt

Maheswar

et al. 2006

ApJ

140

139

View full text Add to dashboard Cite

We present optical spectra of 45 intermediate-mass Herbig Ae/ Be stars. Together with the multiepoch spectroscopic and photometric data compiled for a large sample of these stars and ages estimated for individual stars by using preYmain-sequence evolutionary tracks, we have studied the evolution of emission-line activity in them. We find that, on average, the H emission line strength decreases with increasing stellar age in Herbig Ae/ Be stars, indicating that the accretion activity gradually declines during the preYmain-sequence phase. This would hint at a relatively longlived (a few Myr) process being responsible for the cessation of accretion in Herbig Ae/ Be stars. We also find that the accretion activity in these stars drops substantially by $3 Myr. This is comparable to the timescale in which most intermediate-mass stars are thought to lose their inner disks, suggesting that inner disks in intermediate-mass stars are dissipated rapidly after the accretion activity has fallen below a certain level. We further find a relatively tight correlation between strength of the emission line and near-infrared excess due to inner disks in Herbig Ae/ Be stars, indicating that the disks around Herbig Ae/ Be stars cannot be entirely passive. We suggest that this correlation can be understood within the framework of the puffed-up inner rim disk models if the radiation from the accretion shock is also responsible for the disk heating.

show abstract

A search for clustering around Herbig Ae/Be stars

Cited by 173 publications

References 45 publications

Cometary molecular clouds around RNO 6

Cometary molecular clouds around RNO 6

The Dusty Circumstellar Environments of A[CLC]e[/CLC]/B[CLC]e[/CLC] Protoplanetary Disk Candidates

Evolution of Emission‐Line Activity in Intermediate‐Mass Young Stars

Contact Info

Product

Resources

About