View source for Astronomy:SGR 1935+2154

{{Short description|Soft gamma repeater in the constellation Vulpecula}}{{Starbox begin
| name=SGR 1935+2154}}
{{Starbox image
| image = [[File:Artist’s impression of a fast radio burst traveling through space and reaching_Earth.tif|250px]]
| caption = Example of a [[Astronomy:Fast radio burst|fast radio burst]] (FRB) from outer space to Earth (artist concept)
}}
{{Starbox observe
| epoch=J2000
| ra=19h 35m 
| dec=+21° 54'
| appmag_v= ?
| constell=[[Astronomy:Vulpecula|Vulpecula]]
}}
{{Starbox reference
| Simbad = SGR+1935%2B2154
}}
{{Starbox catalog
|names = <!---PSR 1935+2154--->
}}
{{Starbox end}}
'''SGR 1935+2154''' (or '''SGR J1935+2154''') is a [[Astronomy:Soft gamma repeater|soft gamma repeater]] (SGR) that is an ancient [[Astronomy:Compact star|stellar remnant]], in the constellation [[Astronomy:Vulpecula|Vulpecula]], originally discovered in 2014 by the [[Astronomy:Neil Gehrels Swift Observatory|Neil Gehrels Swift Observatory]].<ref name="SGR 1935+2154 discovery">{{cite news|author=Cummings, J.R. |display-authors=et al.|date=6 July 2014|title=ATel #6294: Newly discovered SGR 1935+2154: Swift observations|work=[[Astronomy:The Astronomer's Telegram|The Astronomer's Telegram]]|url=http://www.astronomerstelegram.org/?read=6294|accessdate=27 February 2021}}</ref> Currently, the SGR-phenomena and the related [[Astronomy:Anomalous X-ray pulsar|anomalous X-ray pulsar]]s (AXP) are explained as arising from [[Astronomy:Magnetar|magnetar]]s. On 28 April 2020, this remnant about {{val|30,000|ul=light-years|fmt=commas}} away in our [[Astronomy:Milky Way|Milky Way]] galaxy was observed to be associated with a very powerful radio pulse known as a [[Astronomy:Fast radio burst|fast radio burst]] or FRB (designated FRB 200428),<ref name="AT-20200429snz">{{cite news|author=Zhang, S.-N.|display-authors=et al.|date=29 April 2020|title=ATel #13687: Insight-HXMT detection of a bright short x-ray counterpart of the Fast Radio Burst from SGR 1935+2154|work=[[Astronomy:The Astronomer's Telegram|The Astronomer's Telegram]]|url=http://www.astronomerstelegram.org/?read=13687|accessdate=4 May 2020}}</ref> and a related x-ray flare.<ref name="SA-20200505">{{cite news |last=Drake |first=Nadia |title='Magnetic Star' Radio Waves Could Solve the Mystery of Fast Radio Bursts - The surprise detection of a radio burst from a neutron star in our galaxy might reveal the origin of a bigger cosmological phenomenon |url=https://www.scientificamerican.com/article/magnetic-star-radio-waves-could-solve-the-mystery-of-fast-radio-bursts/ |date=5 May 2020 |work=Scientific American |accessdate=9 May 2020 }}</ref><ref name="SA-20200501">{{cite news |last=Starr |first=Michelle |title=Exclusive: We Might Have First-Ever Detection of a Fast Radio Burst in Our Own Galaxy |url=https://www.sciencealert.com/a-galactic-magnetar-just-spat-out-something-shockingly-like-a-fast-radio-burst |date=1 May 2020 |work=ScienceAlert.com |accessdate=1 May 2020 }}</ref><ref name="AT-20200428ps">{{cite news |author=Scholz, Paul |display-authors=et al. |title=ATel #13681: A bright millisecond-timescale radio burst from the direction of the Galactic magnetar SGR 1935+2154 |url=http://www.astronomerstelegram.org/?read=13681 |date=28 April 2020 |work=[[Astronomy:The Astronomer's Telegram|The Astronomer's Telegram]] |accessdate=1 May 2020 }}</ref> The detection is notable as the first FRB detected ''inside'' the Milky Way, and the first to be linked to a known source.<ref name="QM-20200611">{{cite news |last=Hall |first=Shannon |title=A Surprise Discovery Points to the Source of Fast Radio Bursts - After a burst lit up their telescope "like a Christmas tree," astronomers were able to finally track down the source of these cosmic oddities. |url=https://www.quantamagazine.org/a-surprise-discovery-shows-magnetars-create-fast-radio-bursts-20200611/ |date=11 June 2020 |work=Quantum Magazine |accessdate=11 June 2020 }}</ref><ref name="AT-20201104">{{cite news |last=Timmer |first=John |title=We finally know what has been making fast radio bursts - Magnetars, a type of neutron star, can produce the previously enigmatic bursts. |url=https://arstechnica.com/science/2020/11/its-coming-from-inside-the-galaxy-first-fast-radio-burst-source-idd/ |date=4 November 2020 |work=[[Ars Technica]] |accessdate=4 November 2020 }}</ref><ref name="NASA-20201104">{{cite news |last1=Cofield |first1=Calla |last2=Andreoli |first2=Calire |last3=Reddy |first3=Francis |title=NASA Missions Help Pinpoint the Source of a Unique X-ray, Radio Burst |url=https://www.jpl.nasa.gov/news/news.php?feature=7776 |date=4 November 2020 |work=[[Organization:NASA|NASA]] |accessdate=4 November 2020 }}</ref><ref name="NAT-20201104">{{cite journal |author=Andersen, B. |display-authors=et al.|title=A bright millisecond-duration radio burst from a Galactic magnetar |url=https://www.nature.com/articles/s41586-020-2863-y |date=4 November 2020 |journal=Nature |volume=587 |issue=7832|pages=54–58 |doi=10.1038/s41586-020-2863-y |pmid=33149292|arxiv=2005.10324|bibcode=2020Natur.587...54C |s2cid=218763435|accessdate=5 November 2020 }}</ref> Later in 2020, SGR 1935+2154 was found to be associated with ''repeating'' fast radio bursts.<ref name="SA-20201116">{{cite news |last=Starr |first=Michelle |title=It's Official: The Fast Radio Burst Coming From Within Our Galaxy Is Repeating |url=https://www.sciencealert.com/it-s-official-magnetar-sgr-1935-2154-is-a-fast-radio-burst-repeater |date=16 November 2020 |work=ScienceAlert |accessdate=17 November 2020 }}</ref>

==History==
The [[Astronomy:Neil Gehrels Swift Observatory#Burst Alert Telescope (BAT)|Swift Burst Alert Telescope]] first alerted the astronomical community to an increase in activity from the remnant with the detection of a flare on 27 April 2020.<ref>{{Cite journal|last=Palmer|first=David|date=27 April 2020|title=Swift detection of multiple bursts from SGR 1935+2154|url=https://gcn.gsfc.nasa.gov/gcn3/27657.gcn3|journal=GCN Circulars|volume=27657|page=1|bibcode=2020GCN.27657....1B}}</ref> The next day, the [[Astronomy:Canadian Hydrogen Intensity Mapping Experiment|Canadian Hydrogen Intensity Mapping Experiment]] (CHIME)<ref name="SA-20200501" /><ref name="AT-20200428ps" /> first reported the detection of two bright radio bursts from 400&nbsp;MHz to 800&nbsp;MHz in the direction of the remnant, establishing the link between radio emission and the remnant. They estimated that the bursts had an energy similar to the brightest giant pulses from the [[Astronomy:Crab Pulsar|Crab pulsar]],<ref name="AT-20200428ps" /><ref>{{Cite journal|last1=Cordes|first1=J. M.|last2=Bhat|first2=N. D. R.|last3=Hankins|first3=T. H.|last4=McLaughlin|first4=M. A.|last5=Kern|first5=J.|date=September 2004|title=The Brightest Pulses in the Universe: Multifrequency Observations of the Crab Pulsar's Giant Pulses|journal=The Astrophysical Journal|volume=612|issue=1|pages=375–388|doi=10.1086/422495|arxiv=astro-ph/0304495|bibcode=2004ApJ...612..375C|s2cid=252457|issn=0004-637X}}</ref> which had never been seen from a magnetar. An independent detection of the bursts at 1.4&nbsp;GHz by the STARE2<ref>{{Cite journal|last1=Bochenek|first1=Christopher D.|last2=McKenna|first2=Daniel L.|last3=Belov|first3=Konstantin V.|last4=Kocz|first4=Jonathon|last5=Kulkarni|first5=Shri R.|last6=Lamb|first6=James|last7=Ravi|first7=Vikram|last8=Woody|first8=David|date=2020-03-01|title=STARE2: Detecting Fast Radio Bursts in the Milky Way|journal=Publications of the Astronomical Society of the Pacific|volume=132|issue=1009|pages=034202|doi=10.1088/1538-3873/ab63b3|arxiv=2001.05077|bibcode=2020PASP..132c4202B|s2cid=210718502|issn=0004-6280}}</ref> team established that the burst, now named FRB 200428, is similar to the fast radio bursts (FRBs) at extragalactic distances with their report that the fluence of the burst must be >1.5 MJy ms,<ref name=":0">{{Cite web|title=ATel #13684: Independent detection of the radio burst reported in ATel #13681 with STARE2|url=http://www.astronomerstelegram.org/?read=13684|website=ATel|access-date=2020-05-15}}</ref> more than a thousand times that reported by CHIME. At the distance of the closest known fast radio burst, FRB 200428 would have been detected with a fluence of >7 mJy ms.<ref name=":0" /> The [[Astronomy:INTEGRAL|INTEGRAL]], [[Engineering:Wind (spacecraft)|Konus-Wind]], [[Astronomy:Hard X-ray Modulation Telescope|Insight-HXMT]], and [[Astronomy:AGILE (satellite)|AGILE]] telescopes then reported the detection of an X-ray burst from SGR 1935+2154 that occurred at the same time as the CHIME and STARE2 bursts,<ref>{{Cite web|title=ATel #13685: INTEGRAL IBIS and SPI-ACS detection of a hard X-ray counterpart of the radio burst from SGR 1935+2154|url=http://www.astronomerstelegram.org/?read=13685|website=ATel|access-date=2020-05-15}}</ref><ref>{{Cite web|title=ATel #13686: AGILE detection of a hard X-ray burst in temporal coincidence with a radio burst from SGR 1935+2154|url=http://www.astronomerstelegram.org/?read=13686|website=ATel|access-date=2020-05-15}}</ref><ref>{{Cite web|title=ATel #13687: Insight-HXMT detection of a bright short x-ray counterpart of the Fast Radio Burst from SGR 1935+2154|url=http://www.astronomerstelegram.org/?read=13687|website=ATel|access-date=2020-05-15}}</ref><ref>{{Cite web|title=ATel #13688: Konus-Wind observation of hard X-ray counterpart of the radio burst from SGR 1935+2154|url=http://www.astronomerstelegram.org/?read=13688|website=ATel|access-date=2020-05-15}}</ref> marking the first time an FRB had been associated with an X-ray source. To further secure the association of FRB 200428 with the remnant, the [[Astronomy:Five-hundred-meter Aperture Spherical Telescope|Five-hundred-meter Aperture Spherical Telescope]] (FAST) reported the detection of a much weaker radio burst,<ref name="AT-20200503">{{cite news|author=Zhang, C.F.|display-authors=et al|date=3 May 2020|title=ATel #13699: A highly polarised radio burst detected from SGR 1935+2154 by FAST|work=[[Astronomy:The Astronomer's Telegram|The Astronomer's Telegram]]|url=http://www.astronomerstelegram.org/?read=13699|accessdate=3 May 2020}}</ref> which was localized to within a maximal [[Margin of error|margin of error]] of a few arcminutes of the position of the remnant with a dispersion measure consistent with those reported by STARE2 and CHIME.

The [[Astronomy:NuSTAR|NuSTAR]], Swift, and [[Astronomy:Neutron Star Interior Composition Explorer|NICER]] satellites observed several short X-ray bursts from the remnant on 29 April 2020 and 30 April 2020, confirming the magnetar was still in an active phase.<ref>{{Cite web|title=ATel #13720: Â X-ray monitoring of the active magnetar SGR 1935+2154|url=http://www.astronomerstelegram.org/?read=13720|website=ATel|access-date=2020-05-15}}</ref> The [[Astronomy:Very Large Array|Very Large Array]] (VLA) followed the remnant 1–2 days after FRB 200428 and did not find any pulsed radio emission or an afterglow.<ref>{{Cite web|title=ATel #13690: VLA search for persistent and bursting emission from SGR 1935+2154|url=http://www.astronomerstelegram.org/?read=13690|website=ATel|access-date=2020-05-15}}</ref><ref>{{Cite web|title=ATel #13693: VLA Monitoring of SGR 1935+2154 on 2020, April 30|url=http://www.astronomerstelegram.org/?read=13693|website=ATel|access-date=2020-05-15}}</ref> The [[Astronomy:NASA Deep Space Network|Deep Space Network]] (DSN) observed the remnant 1.5 to 3.5 days after the FRB and did not find evidence of periodic emission.<ref>{{Cite web|title=ATel #13713: A Search for Radio Bursts and Periodic Emission from SGR 1935+214 at High Radio Frequencies using the Deep Space Network|url=http://www.astronomerstelegram.org/?read=13713|website=ATel|access-date=2020-05-15}}</ref> [[Astronomy:Low-Frequency Array (LOFAR)|LOFAR]] searched for other pulses from the remnant 1.5 days after FRB 200428 at 145&nbsp;MHz and did not find any.<ref>{{Cite web|title=ATel #13707: A LOFAR high time resolution search for radio bursts from SGR 1935+2154|url=http://www.astronomerstelegram.org/?read=13707|website=ATel|access-date=2020-05-15}}</ref> [[Astronomy:Arecibo Observatory|Arecibo]] did not detect any bursts during a period of activity from the remnant in October 2019.<ref>{{Cite web|title=ATel #13726: Arecibo search for radio bursts following a previous SGR-like activity from SGR 1935+2154|url=http://www.astronomerstelegram.org/?read=13726|website=ATel|access-date=2020-05-15}}</ref> [[Astronomy:Spektr-RG|Spektr-RG]] observed the remnant four days prior to FRB 200428 and found no evidence of flaring activity.<ref>{{Cite web|title=ATel #13723: SRG observations of SGR 1935+2154: four days prior to the FRB event|url=http://www.astronomerstelegram.org/?read=13723|website=ATel|access-date=2020-05-15}}</ref> Follow-up studies and observations have been reported.<ref name="AT-20200517">{{cite news |author=Naldi, Giovanni |display-authors=et al. |title=ATel #13739: Search for radio bursts from SGR 1935+2154 at 408 MHz with the Northern Cross |url=http://www.astronomerstelegram.org/?read=13739 |date=17 May 2020 |work=[[Astronomy:The Astronomer's Telegram|The Astronomer's Telegram]] |accessdate=17 May 2020 }}</ref><ref name="AT-20200521">{{cite news |last=Tohuvavohu |first=Aaron |title=ATel #13748: SGR 1935+2154: A catalog of X-ray burst times from Swift/BAT during the ongoing 2020 activity period |url=http://www.astronomerstelegram.org/?read=13748 |date=21 May 2020 |work=[[Astronomy:The Astronomer's Telegram|The Astronomer's Telegram]] |accessdate=22 May 2020 }}</ref><ref name="AT-2200523at">{{cite news |last=Tohuvavohu |first=Aaron |title=ATel #13758: SGR 1935+2154: A complete catalog of X-ray burst times from Swift/BAT imaging |url=http://www.astronomerstelegram.org/?read=13758 |date=23 May 2020 |work=[[Astronomy:The Astronomer's Telegram|The Astronomer's Telegram]] |accessdate=24 May 2020 }}</ref><ref name="AT-20200530">{{cite news |author=Surnis, Mayuresh |display-authors=et al. |title=ATel #13769: A search for radio pulsations from SGR J1935+2154 |url=http://www.astronomerstelegram.org/?read=13769 |date=30 May 2020 |work=[[Astronomy:The Astronomer's Telegram|The Astronomer's Telegram]] |accessdate=30 May 2020 }}</ref><ref name="AT-20200601">{{cite news |author=Bera, Apurba |display-authors=et al. |title=ATel #13773: A uGMRT search for low-frequency persistent radio emission and afterglow from SGR 1935+2154 |url=http://www.astronomerstelegram.org/?read=13773 |date=1 June 2020 |work=[[Astronomy:The Astronomer's Telegram|The Astronomer's Telegram]] |accessdate=1 June 2020 }}</ref><ref name="AT-20200603ms">{{cite news |author=Surnis, Mayuresh |display-authors=et al. |title=ATel #13777: Radio pulsation and imaging study of SGR J1935+2154 with the uGMRT |url=http://www.astronomerstelegram.org/?read=13777 |date=3 June 2020 |work=[[Astronomy:The Astronomer's Telegram|The Astronomer's Telegram]] |accessdate=4 June 2020 }}</ref><ref name-"AT-20200604jr">{{cite news |author=Roy, Jayanta |display-authors=et al. |title=ATel #13778: Search for radio pulsations from SGR 1935+2154 with the uGMRT |url=http://www.astronomerstelegram.org/?read=13778 |date=4 June 2020 |work=[[Astronomy:The Astronomer's Telegram|The Astronomer's Telegram]] |accessdate=4 June 2020 }}</ref> On 4 June 2020, astronomers reported "periodic radio pulsations" from the remnant with the [[Astronomy:Medicina Radio Observatory|Medicina Northern Cross]] (MNC) radio observatory on 30 May 2020.<ref name="NYT-20200604mb">{{cite news |author=Burgay, M. |display-authors=et al. |title=ATel #13783: Marginal detection of radio pulsations from the magnetar SGR 1935+2154 with the Medicina Northern Cross |url=http://www.astronomerstelegram.org/?read=13783 |date=4 June 2020 |work=[[Astronomy:The Astronomer's Telegram|The Astronomer's Telegram]] |accessdate=5 June 2020 }}</ref> Another study was reported on 6 June 2020 of observations made earlier with the [[Astronomy:European VLBI Network|European VLBI Network]] on 13 May 2020.<ref name="AT-20200606">{{cite news |author=Nimmo, K. |display-authors=et al. |title=ATel #13786: A search for persistent radio emission and millisecond-duration radio bursts from SGR 1935+2154 using the European VLBI Network |url=http://www.astronomerstelegram.org/?read=13786 |date=6 June 2020 |work=[[Astronomy:The Astronomer's Telegram|The Astronomer's Telegram]] |accessdate=6 June 2020 }}</ref> There have been other reported observations as well.<ref name="AT-20200610">{{cite news |author=Surnis, Mayurexh |display-authors=et al. |title=ATel #13799: Radio pulsation and imaging study of SGR J1935+2154 with the uGMRT |url=http://www.astronomerstelegram.org/?read=13799 |date=10 June 2020 |work=[[Astronomy:The Astronomer's Telegram|The Astronomer's Telegram]] |accessdate=11 June 2020 }}</ref><ref Name="AT-20200619">{{cite news |author=An, Tao |display-authors=et al. |title=ATel #13816: MWA low-frequency radio imaging of SGR 1935+2154 |url=http://www.astronomerstelegram.org/?read=13816 |date=19 June 2020 |work=[[Astronomy:The Astronomer's Telegram|The Astronomer's Telegram]]|accessdate=19 June 2020 }}</ref><ref name="AT-20200629">{{cite news |author=Tan, Chia Min |display-authors=et al.|title=ATel #13838 - Non-detection of radio pulsations from SGR1935+2154 by CHIME/Pulsar |url=http://www.astronomerstelegram.org/?read=13838 |date=29 June 2020 |work=[[Astronomy:The Astronomer's Telegram|The Astronomer's Telegram]] |accessdate=29 June 2020 }}</ref><ref name="AT-20201105">{{cite news |author=Straal. Samayra |display-authors=et al. |title=ATel #14151 - Search for burst and periodic radio emission from SGR1935+2154 using GBT observations at 800 MHz and S-band |url=http://www.astronomerstelegram.org/?read=14151 |date=5 November 2020 |work=[[Astronomy:The Astronomer's Telegram|The Astronomer's Telegram]] |accessdate=6 November 2020 }}</ref><ref name="AT20201117">{{cite news |last1=Alexander |first=Rodin |last2=Fedorova |first2=Viktoriya |title=ATel #14186: Detection of radio emission from SGR 1935+2154 at the frequency 111 MHz |url=http://www.astronomerstelegram.org/?read=14186 |date=17 November 2020|work=[[Astronomy:The Astronomer's Telegram|The Astronomer's Telegram]] |accessdate=17 November 2020 }}</ref><ref name="AT-20210209">{{cite news |author=Kirsten, Franz |display-authors=et al. |title=ATel #14382: Upper limits on the radio fluence of the most recent X-ray bursts from SGR1935+21 |url=http://www.astronomerstelegram.org/?read=14382 |date=9 February 2021 |work=[[Astronomy:The Astronomer's Telegram|The Astronomer's Telegram]] |accessdate=15 February 2021 }}</ref><ref name="AT-20210212">{{cite news |author=Borghese. A. |display-authors=et al. |title=ATel#14388: Swift observation of the magnetar SGR 1935+2154 following the detection of several bursts |url=http://www.astronomerstelegram.org/?read=14388 |date=12 February 2021 |work=[[Astronomy:The Astronomer's Telegram|The Astronomer's Telegram]] |accessdate=13 February 2021 }}</ref>

==See also==
* {{annotated link|Astronomy:SGR J1745−2900}}

==References==
{{reflist|colwidth=30em}}

==External links==
* [http://simbad.u-strasbg.fr/simbad/sim-id?Ident=SGR+1935%2B2154 SGR 1935+2154 - SIMBAD Astronomical Database]

{{Sky|19|35|0.00|+|21|54|00.0|30000}} 
{{Stars of Vulpecula}}
{{2020 in space}}

{{DEFAULTSORT:SGR 1935+2154}}
[[Category:Magnetars]]
[[Category:Soft gamma repeaters]]
[[Category:Vulpecula]]

{{Sourceattribution|SGR 1935+2154}}