Sudden Extreme Obscuration of a Sun-like Main-sequence Star: Evolution of the Circumstellar Dust around ASASSN-21qj

被引：1

作者：

Marshall, Jonathan P. ^{[1
,2
]}

Ertel, Steve ^{[3
,4
]}

Kemper, Francisca ^{[5
,6
,7
]}

del Burgo, Carlos ^{[8
]}

Otten, Gilles P. P. L. ^{[1
]}

Scicluna, Peter ^{[9
]}

Zeegers, Sascha T. ^{[10
]}

Ribas, Alvaro ^{[11
]}

Morata, Oscar ^{[5
]}

机构：

[1] Acad Sinica, Inst Astron & Astrophys, 11F AS NTU Astron Math Bldg 1,Sect 4 Roosevelt Rd, Taipei 1061, Taiwan

[2] Univ Southern Queensland, Ctr Astrophys, West St, Toowoomba, Qld 4350, Australia

[3] Univ Arizona, Dept Astron & Steward Observ, 933 N Cherry Ave, Tucson, AZ 85721 USA

[4] Univ Arizona, Large Binocular Telescope Observ, 933 N Cherry Ave, Tucson, AZ 85721 USA

[5] CSIC, Inst Ciencies Espai ICE, Can Magrans S-N, E-08193 Cerdanyola Del Valles, Barcelona, Spain

[6] ICREA, Pg Lluis Co 23, E-08010 Barcelona, Spain

[7] Inst Estudis Espacials Catalunya IEEC, E-08034 Barcelona, Spain

[8] Inst Nacl Astrofis Opt & Electr, Luis Enr Erro1, Tonantzintla 72840, Puebla, Afghanistan

[9] European Southern Observ, Alonso Cordova 3107, Santiago, Chile

[10] European Space Agcy, ESTEC, SRE SA, Keplerlaan 1, NL-2201 AZ Noordwijk, Netherlands

[11] Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England

来源：

ASTROPHYSICAL JOURNAL | 2023年 / 954卷 / 02期

基金：

欧盟地平线“2020”;

关键词：

INFRARED INTERFEROMETRIC SURVEY; INTERSTELLAR SILICATE MINERALOGY; 8462852 BOYAJIANS STAR; TERRESTRIAL ZONE; VARIABLE-STARS; DIPPER STARS; DEBRIS; SEARCH; VARIABILITY; PLANET;

D O I：

10.3847/1538-4357/ace629

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

ASASSN-21qj is a distant Sun-like star that recently began an episode of deep dimming events after no prior recorded variability. Here we examine archival and newly obtained optical and near-infrared data of this star. The deep aperiodic dimming and absence of previous infrared excess are reminiscent of KIC 8462852 ("Boyajian's Star"). The observed occultations are consistent with a circumstellar cloud of submicron-sized dust grains composed of amorphous pyroxene, with a minimum mass of 1.50 +/- 0.04 x 10(-9) M-circle plus derived from the deepest occultations, and a minimum grain size of 0.29(-0.18)(+0.01) mu m assuming a power-law size distribution. We further identify the first evidence of near-infrared excess in this system from NEOWISE 3.4 and 4.6 mu m observations. The excess emission implies a total circumstellar dust mass of around 10(-6) M-circle plus, comparable to the extreme, variable disks associated with terrestrial planet formation around young stars. The quasiperiodic recurrence of deep dips and the inferred dust temperature (ranging from 1800 to 700 K across the span of observations) independently point to an orbital distance of similar or equal to 0.2 au for the dust, supporting the occulting material and excess emission being causally linked. The origin of this extended, opaque cloud is surmised to be the breakup of one or more exocometary bodies.

引用

页数：10