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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

32716 results found.

  1. GRB 240511A: Fermi GBM Observation
  2. GRB 240511A: Swift-BAT refined analysis
  3. Fermi GRB 240513B: Global MASTER-Net observations report
  4. GRB 240511A: J-band observations with WINTER
  5. GRB 240511A : MITSuME Akeno optical upper limits
  6. LIGO/Virgo/KAGRA S240512r: Updated Sky localization and EM Bright Classification
  7. GRB 240511A: optical afterglow detection from the NOT
  8. LIGO/Virgo/KAGRA S240512r: Identification of a GW compact binary merger candidate
  9. Fermi GRB 240511A: Global MASTER-Net observations report
  10. Swift GRB 240511A: Global MASTER-Net observations report
  11. LIGO/Virgo/KAGRA S240511i: Updated Sky localization
  12. LIGO/Virgo/KAGRA S240511i: Identification of a GW compact binary merger candidate
  13. LIGO/Virgo/KAGRA S240422ed: GMOS-S photometry of J-GEM24a
  14. LIGO/Virgo/KAGRA S240422ed: Candidates from the latest GW-MMADS DECam Observations
  15. EP240506a: Xinglong optical upper limit
  16. EP240506a: CrAO ZTSH optical upper limit
  17. GRB 240504A: Fermi GBM Observation
  18. EP240506a: Archival radio searching
  19. EP240506a: TRT optical upper limit
  20. LIGO/Virgo/KAGRA S240507p: Updated Sky localization and EM Bright Classification
  21. EP240506a: Optical upper limit with Kinder observations
  22. IPN triangulation of GRB 240504A
  23. GRB 240502A: 1.3m DFOT Optical upper limit
  24. LIGO/Virgo/KAGRA S240507p: Identification of a GW compact binary merger candidate
  25. LIGO/Virgo/KAGRA S240422ed: Additional WINTER near-infrared J-band observations
  26. LIGO/Virgo/KAGRA S240422ed: Swope Follow-up of AT2024hfr and AT2024hfs
  27. LIGO/Virgo/KAGRA S240505av: Updated Sky localization and EM Bright Classification
  28. LIGO/Virgo/KAGRA S240505av: Identification of a GW compact binary merger candidate
  29. IceCube-240424A: GRANDMA Optical Upper Limit of Fermi J2151.3+0220
  30. GRB 240502C: Zeiss-1000 at Koshka observatory observations of GOTO optical counterpart candidates
  31. IPN triangulation of GRB 240501B and GRB 240501A - possible episodes of ultra long GRB
  32. Fermi GRB 240504A: Global MASTER-Net observations report
  33. LXT 240402A / GRB 240402B: VLT X-shooter redshift of host
  34. GRB 240502A: GOTO optical upper limit
  35. GRB 240502A: Fermi GBM Observation
  36. GRB 240415A 1.3m DFOT Optical upper limit
  37. GRB 240502C: GOTO possible optical counterpart candidates
  38. LIGO/Virgo/KAGRA S240501an: Updated Sky localization and EM Bright Classification
  39. LIGO/Virgo/KAGRA S240430ca: Updated Sky localization and EM Bright Classification
  40. Fermi GRB 240502B: Global MASTER-Net observations report
  41. Fermi GRB 240502A: Global MASTER-Net observations report
  42. GRB 240501B: GRBAlpha detection
  43. GRB 240430A: GRBAlpha detection
  44. LIGO/Virgo/KAGRA S240422ed: GECKO/KMTNet Transient Candidates
  45. LIGO/Virgo/KAGRA S240422ed: Host redshifts of AT2024hfq, AT2024hfu, and AT2024hmo from DBSP
  46. Fermi GRB 240501A: Global MASTER-Net observations report
  47. GRB 240426A: VZLUSAT-2 detection
  48. GRB 240425A: VZLUSAT-2 detection
  49. MeerKAT Discovery of a Probable Radio Counterpart to EP240414a
  50. GRB 240408B: VZLUSAT-2 detection
  51. GRB 240407A: VZLUSAT-2 detection
  52. LIGO/Virgo/KAGRA S240501an: Identification of a GW compact binary merger candidate
  53. X-ray transient EP240414a: Detection of associated supernova
  54. LIGO/Virgo/KAGRA S240430ca: Updated Sky localization and EM Bright Classification
  55. LIGO/Virgo/KAGRA S240430ca: Identification of a GW compact binary merger candidate
  56. LIGO/Virgo/KAGRA S240422ed: GECKO/7DT ToO observations
  57. Additional DECam GW-MMADS Candidates from three nights of observations
  58. GRB 240425A: GRBAlpha detection
  59. Fermi-LAT gamma-ray observations of IceCube-240424A
  60. LIGO/Virgo/KAGRA S240426s: Updated Sky localization
  61. LIGO/Virgo/KAGRA S240422ed: SRG/eROSITA archival upper limit for EP240426a
  62. LIGO/Virgo/KAGRA S240426dl: Updated Sky localization
  63. LIGO/Virgo/KAGRA S240428dr: Updated Sky localization
  64. LIGO/Virgo/KAGRA S240422ed: GECKO/KMTNet ToO observations
  65. LIGO/Virgo/KAGRA S240422ed: ENGRAVE VLT/XShooter spectroscopy of the host galaxy of J-GEM24a
  66. LIGO/Virgo/KAGRA S240428dr: Identification of a GW compact binary merger candidate
  67. Fermi GRB 240428A: Global MASTER-Net observations report
  68. LIGO/Virgo/KAGRA S240422ed: J-band non-detection of J-GEM24a
  69. LIGO/Virgo/KAGRA S240422ed: DDOTI Optical Upper Limit for J-GEM24a
  70. EP240426b: AST3-2 optical upper limit
  71. LIGO/Virgo/KAGRA S240422ed: Observations with 1.6m Mephisto
  72. LIGO/Virgo/KAGRA S240422ed: A transient discovered from Subaru/MOIRCS near-infrared observations by J-GEM Collaboration
  73. LIGO/Virgo S240422ed: Swift XRT observation of EP240426a
  74. LIGO/Virgo/KAGRA S240422ed: NOT optical observations of EP240426a
  75. EP240426b: EP-WXT detection of a new fast X-ray transient
  76. LIGO/Virgo/KAGRA S240422ed: Archival radio detection of EP240426a
  77. LIGO/Virgo/KAGRA S240422ed: Swope Follow-up of AT2024hfq, AT2024hfr, AT2024hfs, and AT2024hfx
  78. LIGO/Virgo/KAGRA S240422ed: GRANDMA Optical Upper Limits for EP240426a
  79. LIGO/VIRGO/KAGRA S240422ed: Historical variability for EP240426a
  80. EP240426a: YAHPT optical upper limit
  81. XMM-Newton observation of EP240426a
  82. LIGO/Virgo/KAGRA S240426dl: Identification of a GW compact binary merger candidate
  83. LIGO/Virgo/KAGRA S240422ed: BOOTES-4/MET Optical Upper Limits for EP240426a
  84. LIGO/Virgo/KAGRA S240422ed: EP-FXT Detection of the Potential Opitcal Electromagnetic Counterpart AT 2024hfq Reported by DECam
  85. GRB 240414A: NOEMA detection
  86. LIGO/Virgo/KAGRA S240422ed: EP240426a possible optical detection
  87. LIGO/Virgo/KAGRA S240422ed: Continued Magellan Observations
  88. EP240426a: GMG optical upper limit
  89. LVK S240422ed: Further Swift-XRT followup of three sources
  90. LIGO/Virgo/KAGRA S240422ed: EP-FXT detection of a candidate counterpart EP240426a
  91. LIGO/Virgo/KAGRA S240426s: Identification of a GW compact binary merger candidate
  92. LIGO/Virgo/KAGRA S240422ed: Magellan Follow-up Observations of Swift/XRT candidates
  93. LIGO/Virgo/KAGRA S240422ed: Zwicky Transient Facility contuinued observations of S240422ed and candidate analysis
  94. IceCube-240424A: Upper limits from a search for additional neutrino events in IceCube
  95. LIGO/Virgo/KAGRA S240422ed: GOTO counterpart search update and AT2024hfx, AT2024hgl observations
  96. S240422ed: BlackGEM/MeerLICHT transient detection AT2024hgl/MLTJ080628.10-250116.4
  97. LIGO/Virgo/KAGRA S240422ed: PRIME near-infrared observations
  98. LIGO/Virgo/KAGRA S240422ed: 2.5m PRL Telescope follow-up of the Swift/XRT source S240422ed_X190
  99. S240422ed: MeerLICHT/BlackGEM photometry on AT2024hfx and archival ZTF detection
  100. LIGO/Virgo/KAGRA S240422ed: Second night Pan-STARRS observations of the skymap

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