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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"

24521 results found.

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

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