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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').
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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"

24519 results found.

  1. GRB 240425A: Fermi GBM Final Real-time Localization
  2. Fermi trigger No 735697285: Global MASTER-Net observations report
  3. GRB 240419B: Swift-BAT refined analysis
  4. GRB 240421B: Swift-BAT refined analysis
  5. GRB 240422A: Glowbug gamma-ray detection
  6. LIGO/Virgo/KAGRA S240413p: DESGW DECam Follow-Up
  7. LIGO/Virgo/KAGRA S240422ed: No significant counterpart candidates in HAWC observations
  8. LIGO/Virgo/KAGRA S240422ed: Vetting of DECam Candidates Using Real-Time Resources and SAGUARO Infrastructure
  9. LIGO/Virgo/KAGRA S240422ed: No significant candidates in GRANDMA/FRAM Observations
  10. IceCube-240424A - IceCube observation of a high-energy neutrino candidate track-like event
  11. LIGO/Virgo S240422ed: Swift-XRT detection of 3 possible counterparts
  12. LIGO/Virgo/KAGRA S240422ed: Early X-ray Upper Limits from EP-WXT for the LVK Sky Localization Region
  13. LIGO/Virgo/KAGRA S240422ed: Continued Imaging of Mag24a
  14. LIGO/Virgo/KAGRA S240422ed: NOT J-band upper limit on the Swift/XRT source S240422ed_X61
  15. GRB 240421B: GRBAlpha detection
  16. IceCube Alert 240424.08: Global MASTER-Net observations report
  17. LIGO/Virgo/KAGRA S240422ed: Magellan Detection of a Potential Electromagnetic Counterpart
  18. LIGO/Virgo/KAGRA S240422ed: SAGUARO upper limits from CSS
  19. LIGO/Virgo/KAGRA S240422ed: Subaru/MOIRCS near-infrared observations by J-GEM Collaboration
  20. LIGO/Virgo/KAGRA S240422ed: Potential Candidates from Magellan galaxy-based search
  21. IceCube-240419A: Upper limits from a search for additional neutrino events in IceCube
  22. LIGO/Virgo/KAGRA S240421ar: Updated Sky localization
  23. LIGO/Virgo/KAGRA S240422ed: GW-MMADS DECam upper limits on the Swift/XRT source S240422ed_X61
  24. LIGO/Virgo/KAGRA S240422ed: GOTO counterpart search
  25. LIGO/Virgo/KAGRA S240422ed: No Counterparts in DDOTI/OAN Optical Observations
  26. GRB 240419A: Swift-BAT refined analysis
  27. GRB 240418A: Swift-BAT refined analysis
  28. LIGO/Virgo/KAGRA S240422ed: WINTER near-infrared J-band observations
  29. LIGO/Virgo S240422ed: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  30. LIGO/Virgo/KAGRA S240422ed: Zwicky Transient Facility observations and candidates
  31. LIGO/Virgo/KAGRA S240422ed: Magellan Observations
  32. LIGO/Virgo/KAGRA S240422ed: Updated NED Galaxies in the Localization Volume
  33. LIGO/Virgo/KAGRA S240422ed: AstroSat CZTI non-detection and upper limits
  34. LIGO/Virgo/KAGRA S240422ed: Upper limits from Fermi-GBM Observations
  35. LIGO/Virgo/KAGRA S240422ed: Updated Sky localization and EM Bright Classification
  36. LIGO/Virgo/KAGRA S240421ar: Upper limits from Swift/BAT-GUANO
  37. LIGO/Virgo/KAGRA S240422ed: Coverage and upper limits from MAXI/GSC observations
  38. LIGO/Virgo/KAGRA S240422ed: Identification of a GW compact binary merger candidate
  39. LIGO/Virgo/Kagra S240422ed: NED Galaxies in the Localization Volume
  40. LIGO/Virgo/KAGRA S240422ed: Global MASTER-Net observations report
  41. Fermi trigger No 735470374: Global MASTER-Net observations report
  42. Fermi-LAT gamma-ray observations of IceCube-240419A
  43. GRB 240419B : MITSuME Akeno optical upper limits
  44. GRB 240415B: Swift-XRT observations
  45. Fermi GRB 240422A: Global MASTER-Net observations report
  46. GRB 240422A: Fermi GBM Final Real-time Localization
  47. Fermi GRB 240421B: Global MASTER-Net observations report
  48. Swift GRB 240421B: Global MASTER-Net observations report
  49. GRB 240421B: Fermi GBM Observation
  50. GRB 240421B: J-band upper limits from WINTER
  51. Fermi GRB 240421A: Global MASTER-Net observations report
  52. EP240417a: no counterpart detection by SOAR
  53. EP240420a: Xinglong decaying optical counterpart
  54. EP240420a: Nanshan optical counterpart observations
  55. LIGO/Virgo/KAGRA S240421ar: Identification of a GW unmodeled transient candidate
  56. GRB 240421A: Fermi GBM Final Real-time Localization
  57. EP240420a: detection of fading X-ray emission with refined position by EP-FXT
  58. EP240420a: NOT optical counterpart candidate and potential host
  59. Fermi trigger No 735280430: Global MASTER-Net observations report
  60. GRB240419A: Skynet Optical Afterglow Analysis
  61. GRB240418A - Candidate afterglow from NIRES
  62. IceCube Alert 240419.98: Global MASTER-Net observations report
  63. IceCube-240419A - IceCube observation of a high-energy neutrino candidate track-like event
  64. IceCube-240419A - IceCube observation of a high-energy neutrino candidate track-like event
  65. GRB 240419B: Swift-XRT refined Analysis
  66. GRB 240419B: optical afterglow from the NOT
  67. LIGO/Virgo/KAGRA S240420aw: Retraction of GW compact binary merger candidate
  68. Swift GRB 240419B: Global MASTER-Net observations report
  69. Swift GRB 240419A: Global MASTER-Net observations report
  70. GRB 240419A: REM NIR afterglow detection
  71. EP240417a: YAHPT Optical Upper Limits
  72. GRB240418A: YAHPT Upper Limits
  73. GRB 240419A: VLT optical afterglow detection
  74. Fermi trigger No 735089036: Global MASTER-Net observations report
  75. GRB 240418A: NOT optical upper limits
  76. GRB 240411A: GOTO early optical upper limits
  77. Swift GRB240418.85: Global MASTER-Net observations report
  78. GRB 240418A: Swift detection of a burst
  79. Fermi GRB 240417A: Global MASTER-Net observations report
  80. LIGO/Virgo/KAGRA S240413p: X-ray upper limits from EP-WXT for the candidate AGN counterpart
  81. EP240416a: BOOTES-2/TELMA Optical Upper Limit
  82. IceCube-Cascade 240416A: Upper limits from a search for additional neutrino events in IceCube
  83. GRB 240417A: Fermi GBM Final Real-time Localization
  84. LIGO/Virgo/KAGRA S240413p: historical ATLAS and ZTF observations of the candidate AGN counterpart
  85. GRB 240414A: Glowbug gamma-ray detection
  86. LIGO/Virgo/KAGRA S240413p: STEP - T80S Search and Candidate Counterpart Identification
  87. GRB 240415B: GECAM-B detection
  88. EP 240416a: Xinglong and NOT decaying optical counterpart
  89. GRB 240415A: Swift-BAT refined analysis
  90. EP240416A: MASTER optical observations
  91. GRB 240414A: Swift-BAT refined analysis
  92. EP240416a: Kinder optical counterpart candidate
  93. EP240413a: BOOTES-2/TELMA Optical Upper Limit
  94. GRB 240415A: Fermi GBM Observation
  95. GRB 240414A: GMG observation
  96. EP 240414a: BOOTES-4/MET Optical Upper Limits
  97. EP240414a: EP-FXT follow-up observation
  98. GRB 240415B: Swift/BAT-GUANO arcminute localization of a short burst
  99. GRB 240414A: Fermi GBM Observation
  100. Fermi GRB 240415A: Global MASTER-Net observations report

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