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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"

5173 results found.

  1. Fermi trigger No 737523389: Global MASTER-Net observations report
  2. GRB 240514B: GOTO candidate optical counterpart
  3. GRB 240513A: Fermi GBM observation
  4. GRB 240513A: Swift-XRT observations
  5. LAT GRB240513.31: Global MASTER-Net observations report
  6. Fermi trigger No 737277727: Global MASTER-Net observations report
  7. Fermi trigger No 737247400: Global MASTER-Net observations report
  8. Fermi trigger No 737196587: Global MASTER-Net observations report
  9. Fermi trigger No 737168073: Global MASTER-Net observations report
  10. GRB 240511A: Swift-XRT refined Analysis
  11. Fermi trigger No 737173236: Global MASTER-Net observations report
  12. Fermi trigger No 737152719: Global MASTER-Net observations report
  13. LIGO/Virgo/KAGRA S240422ed: GMOS-S photometry of J-GEM24a
  14. Fermi trigger No 736967879: Global MASTER-Net observations report
  15. Fermi trigger No 736564880: Global MASTER-Net observations report
  16. IceCube-240424A: GRANDMA Optical Upper Limit of Fermi J2151.3+0220
  17. GRB 240502C: Zeiss-1000 at Koshka observatory observations of GOTO optical counterpart candidates
  18. IPN triangulation of GRB 240501B and GRB 240501A - possible episodes of ultra long GRB
  19. GRB 240503A: AstroSat CZTI detection
  20. Fermi GRB 240501A: Global MASTER-Net observations report
  21. Fermi trigger No 736197684: Global MASTER-Net observations report
  22. GRB 240426A: VZLUSAT-2 detection
  23. GRB 240407A: VZLUSAT-2 detection
  24. Fermi-LAT gamma-ray observations of IceCube-240424A
  25. LIGO/Virgo/KAGRA S240422ed: A transient discovered from Subaru/MOIRCS near-infrared observations by J-GEM Collaboration
  26. LIGO/Virgo/KAGRA S240422ed: NOT optical observations of EP240426a
  27. GRB 240426A: AstroSat CZTI detection
  28. LIGO/Virgo/KAGRA S240422ed: BOOTES-4/MET Optical Upper Limits for EP240426a
  29. LIGO/Virgo/KAGRA S240422ed: EP-FXT Detection of the Potential Opitcal Electromagnetic Counterpart AT 2024hfq Reported by DECam
  30. LIGO/Virgo/KAGRA S240422ed: Continued Magellan Observations
  31. LIGO/Virgo/KAGRA S240422ed: Magellan Follow-up Observations of Swift/XRT candidates
  32. IceCube-240424A: Upper limits from a search for additional neutrino events in IceCube
  33. S240422ed: BlackGEM/MeerLICHT transient detection AT2024hgl/MLTJ080628.10-250116.4
  34. LIGO/Virgo/KAGRA S240422ed: 2.5m PRL Telescope follow-up of the Swift/XRT source S240422ed_X190
  35. S240422ed: MeerLICHT/BlackGEM photometry on AT2024hfx and archival ZTF detection
  36. LIGO/Virgo/KAGRA S240422ed: Second night Pan-STARRS observations of the skymap
  37. LIGO/Virgo/KAGRA S240422ed: Further near-infrared observations with Subaru/MOIRCS by J-GEM Collaboration
  38. LIGO/Virgo/KAGRA S240422ed: X-ray Upper Limits from EP-FXT for the Potential Electromagnetic Counterparts Reported by Swift and DECam
  39. LIGO/Virgo/KAGRA S240422ed: Additional DECam GW-MMADS Candidates from the first two nights of observations
  40. Fermi trigger No 735697285: Global MASTER-Net observations report
  41. LIGO/Virgo/KAGRA S240422ed: Himalayan Chandra Telescope follow-up of the Swift/XRT source S240422ed_X101
  42. LIGO/Virgo/KAGRA S240422ed: Vetting of DECam Candidates Using Real-Time Resources and SAGUARO Infrastructure
  43. LIGO/Virgo/KAGRA S240422ed: No significant candidates in GRANDMA/FRAM Observations
  44. IceCube-240424A - IceCube observation of a high-energy neutrino candidate track-like event
  45. LIGO/Virgo/KAGRA S240422ed: MOSFIRE spectroscopy of the DECam GW-MMADS candidate AT 2024hdn
  46. LIGO/Virgo/KAGRA S240422ed: ATCA follow-up of candidate counterparts
  47. LIGO/Virgo S240422ed: Swift-XRT detection of 3 possible counterparts
  48. LIGO/Virgo/KAGRA S240422ed: Early X-ray Upper Limits from EP-WXT for the LVK Sky Localization Region
  49. LIGO/Virgo/KAGRA S240422ed: J-band non-detection of Mag24a
  50. LIGO/Virgo/KAGRA S240422ed: Continued Imaging of Mag24a
  51. LIGO/Virgo/KAGRA S240422ed: DECam GW-MMADS Candidates
  52. IceCube Alert 240424.08: Global MASTER-Net observations report
  53. LIGO/Virgo/KAGRA S240422ed: SAGUARO upper limits from CSS
  54. LIGO/Virgo/KAGRA S240422ed: Subaru/MOIRCS near-infrared observations by J-GEM Collaboration
  55. LIGO/Virgo/KAGRA S240422ed: no candidate counterparts from ATLAS observations
  56. LIGO/Virgo/KAGRA S240422ed: Magellan Observations
  57. Fermi trigger No 735470374: Global MASTER-Net observations report
  58. Fermi GRB 240422A: Global MASTER-Net observations report
  59. GRB 240422A: Fermi GBM Final Real-time Localization
  60. GRB 240421B: Swift-XRT refined Analysis
  61. EP240420a: Xinglong decaying optical counterpart
  62. Fermi trigger No 735280430: Global MASTER-Net observations report
  63. IceCube Alert 240419.98: Global MASTER-Net observations report
  64. GRB 240419B: Swift-XRT refined Analysis
  65. Swift GRB 240419A: Global MASTER-Net observations report
  66. GRB 240419A: Swift-XRT refined Analysis
  67. GRB 240418A: Swift-XRT refined Analysis
  68. GRB 240418A: Swift detection of a burst
  69. LIGO/Virgo/KAGRA S240413p: X-ray upper limits from EP-WXT for the candidate AGN counterpart
  70. EP240416a: BOOTES-2/TELMA Optical Upper Limit
  71. EP240413a: BOOTES-2/TELMA Optical Upper Limit
  72. EP 240414a: BOOTES-4/MET Optical Upper Limits
  73. Fermi GRB 240415A: Global MASTER-Net observations report
  74. LIGO/Virgo/KAGRA S240413p: Global MASTER-Net observations report
  75. Swift Trigger 1220736: detection of 4U 1543-62.
  76. Fermi GRB 240407A: Global MASTER-Net observations report
  77. LXT 240402A: MASTER optical observations with AGN in error-box
  78. Fermi GRB 240402A: Global MASTER-Net observations report
  79. X-ray transient EP20240331a: MeerLICHT optical upper limits
  80. GRB 240324A: AstroSat CZTI detection of a short burst
  81. Fermi GRB 240328B: Global MASTER-Net observations report
  82. Fermi GRB 240328A: Global MASTER-Net observations report
  83. X-ray transient EP240315a: continued ATCA monitoring
  84. Fermi trigger No 733092476: Global MASTER-Net observations report
  85. Fermi trigger No 732937833: Global MASTER-Net observations report
  86. Fermi GRB 240320A: Global MASTER-Net observations report
  87. Konus-Wind detection of GRB 240315C (possible counterpart of EP240315a)
  88. GRB 240317B: Swift/BAT-GUANO Angular Error Correction
  89. X-ray transient EP240315a: Montarrenti Observatory optical upper limit
  90. Fermi GRB 240317B: Global MASTER-Net observations report
  91. Fermi GRB 240317A: Global MASTER-Net observations report
  92. GRB 240317B: Fermi GBM Final Real-time Localization
  93. Fermi trigger No 732299243: Global MASTER-Net observations report
  94. GRB 240309A: MAXI/GSC detection
  95. GRB 231215A: further radio observations with the VLA
  96. Fermi GRB 240306A: Global MASTER-Net observations report
  97. Fermi GRB 240305A: Global MASTER-Net observations report
  98. Improved IPN triangulation of GRB 240227A (short)
  99. Fermi trigger No 731161136: Global MASTER-Net observations report
  100. Fermi GRB 240229A: Global MASTER-Net observations report

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