A New Class of Large-amplitude Radial-mode Hot Subdwarf Pulsators

Kupfer, Thomas; Bauer, Evan B.; Burdge, Kevin B.; Bellm, Eric C.; Bildsten, Lars; Fuller, Jim; Hermes, J. J.; Kulkarni, S. R.; Prince, Thomas A.; Roestel, Jan van; Dekany, Richard; Duev, Dmitry A.; Feeney, Michael; Giomi, M.; Graham, M. J.; Kaye, Stephen B.; Laher, Russ R.; Masci, Frank J.; Porter, Michael; Riddle, Reed; Shupe, D. L.; Smith, Roger M.; Soumagnac, Maayane T.; Szkody, Paula; Ward, Charlotte

doi:10.3847/2041-8213/ab263c

Cited by 47 publications

(104 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In both cases, it can be seen that the peak of the driving (indicated by the maximum of the derivative of the work function) corresponds to the location of the peak in the iron abundance and corresponding opacity bump. This confirms that the driving mechanism for both the low-gravity BLAPs of Pietrukowicz et al (2017) and the high-gravity BLAPs of Kupfer et al (2019) is the κ-mechanism, with the opacity bump enhanced by the action of radiative levitation on iron and nickel.…”

Section: The Faint Blue Variable Instability Regionsupporting

confidence: 73%

“…There are a number of other areas with unstable models in this data, such as in the white dwarf cooling sequence. As the primary goal of this work was to investigate the population of high amplitude pulsators of Pietrukowicz et al (2017) and Kupfer et al (2019), these models were not investigated in detail in this work. Additionally, as was demonstrated by changing the envelope mass, there are a number of other variables which may play a role and have an impact on the exact morphology of the instability regions.…”

Section: Other Potential Effectsmentioning

confidence: 99%

“…These higher surface gravities and surface temperatures place them amongst the hot subdwarf pulsators in the log g − log T eff diagram. Table 1 compares the general population properties of the Kupfer et al (2019) and Pietrukowicz et al (2017) pulsators and both classes of hot subdwarf variables, while Table 2 lists the properties of the individual stars for which spectroscopic follow-up has been completed. This new discovery raises an interesting question of whether these two groups of faint, large-amplitude pulsators are related to each other and/or to the hot subdwarfs.…”

Section: Introductionmentioning

confidence: 99%

“…This new discovery raises an interesting question of whether these two groups of faint, large-amplitude pulsators are related to each other and/or to the hot subdwarfs. Kupfer et al (2019) computed some helium-core pre-WD models and found that lower mass (∼ 0.28 M ) pre-WDs provide a very good match in terms of the pulsation periods, while a model of a shell He-burning, post-EHB star gives pulsation periods which are longer than those observed, making this a less likely candidate. Thus the current opinion appears to be that the pulsators of Pietrukowicz et al (2017) and Kupfer et al (2019) are related objects, different only in mass.…”

Section: Introductionmentioning

confidence: 99%

“…Kupfer et al (2019) computed some helium-core pre-WD models and found that lower mass (∼ 0.28 M ) pre-WDs provide a very good match in terms of the pulsation periods, while a model of a shell He-burning, post-EHB star gives pulsation periods which are longer than those observed, making this a less likely candidate. Thus the current opinion appears to be that the pulsators of Pietrukowicz et al (2017) and Kupfer et al (2019) are related objects, different only in mass. This raises the question of whether these are two distinct groups of pulsator or part of a contiguous region of instability, which may become populated as these large-scale sky surveys such as ZTF and OGLE continue to monitor the sky.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Pulsation in faint blue stars

Byrne

Jeffery

2019

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

Following the discovery of blue large-amplitude pulsators (BLAPs) by the OGLE survey, additional hot, high-amplitude pulsating stars have been discovered by the Zwicky Transient Facility. It has been proposed that all of these objects are low-mass pre-white dwarfs and that their pulsations are driven by the opacity of iron-group elements. With this expanded population of pulsating objects, it was decided to compute a sequence of post-common-envelope stellar models using the mesa stellar evolution code and to examine the pulsation properties of low-mass pre-white dwarfs using non-adiabatic analysis with the gyre stellar oscillation code. By including the effects of atomic diffusion and radiative levitation, it is shown that a large region of instability exists from effective temperatures of 30 000 K up to temperatures of at least 50 000 K and at a wide range of surface gravities. This encompasses both groups of pulsator observed so far, and confirms that the driving mechanism is through iron group element opacity. We make some conservative estimates about the range of periods, masses, temperatures and gravities in which further such pulsators might be observed.

show abstract

Section: The Faint Blue Variable Instability Regionsupporting

confidence: 73%

Section: Other Potential Effectsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Pulsation in faint blue stars

Byrne

Jeffery

2019

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

show abstract

Multi-periodicity in the high gravity blue large amplitude pulsator ZTF J071329.02-152125.2

Koen

2024

Publ. Astron. Soc. Aust.

View full text Add to dashboard Cite

New time series photometry of the pulsating hot subdwarf star ZTF J071329.02-152125.2 is presented. Rapid (timescale of hours) changes in the amplitude of the known pulsation in the star was observed. This could be ascribed to beating between three closely spaced frequencies, but analysis of all available photometry finds a range of different frequencies, with widely different amplitudes. A new frequency of 49.66 d−1, suggestive of gravity-mode pulsation, was also discovered. The star may be a hybrid p-mode/g-mode hot subdwarf pulsator which sometimes exhibits extraordinarily large amplitude variability.

show abstract

An 18.9 min blue large-amplitude pulsator crossing the ‘Hertzsprung gap’ of hot subdwarfs

Lin

Wang

et al. 2022

Nat Astron

View full text Add to dashboard Cite

Blue large-amplitude pulsators (BLAPs) represent a new and rare class of hot pulsating stars with unusually large amplitudes and short periods. Up to now, only 21 confirmed BLAPs have been identified from more than one billion monitored stars, including a group with pulsation period longer than 20 min (classical BLAPs; [1]) and the other group with pulsation period below 10 min (high-gravity BLAPs; [2]). The evolutionary path that could give rise to such kinds of stellar configurations is unclear. Here we report on a comprehensive study of the peculiar BLAP discovered by the Tsinghua University -Ma Huateng Telescopes for Survey (TMTS) [3], TMTS J035143.63+584504.2 (TMTS-BLAP-1); it is the first confirmed BLAP located within the "period gap" between high-gravity and classical BLAPs. This new BLAP has an 18.9 min pulsation period, and is similar to the classical BLAPs with an extended helium-enriched envelope. In particular, the long-term monitoring data of TMTS-BLAP-1 reveal that this pulsating star has an unusually large rate of period change, Ṗ /P = 2.3 × 10 −6 yr −1 . Such a significant and positive value challenges the scenarios of both the helium-core pre-white-dwarf and the core-helium burning [1, 2, 4-6]), but is consistent with that derived from shell-helium burning. The particular pulsation period and unusual rate of period change indicate that TMTS-BLAP-1 is at a short-lived (∼ 10 6 yr) phase of shell-helium ignition before the stable shell-helium burning; in other words, TMTS-BLAP-1 is going through a "Hertzsprung gap" of hot subdwarfs. This demonstrates that hot subdwarf stars have a similar evolutionary fate as main-sequence stars; some subdwarfs can leave their "main-sequence" stage and appear as diverse pulsating variables in distinct regions of the Hertzsprung-Russell diagram, thereby opening a new window for explorations of rare pulsating stars that evolved from stripped-envelope stars.The minute-cadence observations by Tsinghua University -Ma Huateng Telescopes for Survey (TMTS) enable the search of variable stars with periods shorter than 1 hr. TMTS J035143.63+584504.2 is such a newly discovered short-period variable, having an 18.9 min period and a peak-to-peak amplitude up to ∼ 0.3 mag in white light [3]. Follow-up observations with SNOVA,

show abstract

A New Class of Large-amplitude Radial-mode Hot Subdwarf Pulsators

Cited by 47 publications

References 56 publications

Pulsation in faint blue stars

Pulsation in faint blue stars

Multi-periodicity in the high gravity blue large amplitude pulsator ZTF J071329.02-152125.2

An 18.9 min blue large-amplitude pulsator crossing the ‘Hertzsprung gap’ of hot subdwarfs

Contact Info

Product

Resources

About