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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.

Advanced Search Examples (click to copy):

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

45792 results found.

  1. GRB 240421B: J-band upper limits from WINTER
  2. GRB 240421B: Swift/UVOT Upper Limits
  3. GRB 240421B: Enhanced Swift-XRT position
  4. Fermi GRB 240421A: Global MASTER-Net observations report
  5. EP240417a: no counterpart detection by SOAR
  6. EP240420a: TNT upper limit to its optical counterpart
  7. EP240420a: Xinglong decaying optical counterpart
  8. GRB 240421B: Swift detection of a burst
  9. EP240420a: Nanshan optical counterpart observations
  10. EP240420a: GWAC-F50A optical upper limit
  11. LIGO/Virgo/KAGRA S240421ar: Identification of a GW unmodeled transient candidate
  12. GRB 240421A: Fermi GBM Final Real-time Localization
  13. EP240420a: detection of fading X-ray emission with refined position by EP-FXT
  14. EP240420a: NOT optical counterpart candidate and potential host
  15. Fermi trigger No 735280430: Global MASTER-Net observations report
  16. GRB240419A: Skynet Optical Afterglow Analysis
  17. GRB240418A - Candidate afterglow from NIRES
  18. IceCube Alert 240419.98: Global MASTER-Net observations report
  19. GRB 240419B: Swift/UVOT Upper Limits
  20. IceCube-240419A - IceCube observation of a high-energy neutrino candidate track-like event
  21. IceCube-240419A - IceCube observation of a high-energy neutrino candidate track-like event
  22. EP240420a: EP-WXT detection of a fast X-ray transient
  23. GRB 240419A: Swift/UVOT Upper Limits
  24. GRB 240419B: Swift-XRT refined Analysis
  25. GRB 240419B: optical afterglow from the NOT
  26. LIGO/Virgo/KAGRA S240420aw: Retraction of GW compact binary merger candidate
  27. EP240414a: Near-IR observations with NIRES and WINTER
  28. Swift GRB 240419B: Global MASTER-Net observations report
  29. EP240414A: Terskol Zeiss-2000 optical upper limit
  30. GRB 240419B: Enhanced Swift-XRT position
  31. Swift GRB 240419A: Global MASTER-Net observations report
  32. GRB 240418A: Swift/UVOT Upper Limits
  33. GRB 240419A: REM NIR afterglow detection
  34. GRB 240419A: Swift-XRT refined Analysis
  35. GRB 240418A: Swift-XRT refined Analysis
  36. GRB 240419B: Swift detection of a burst
  37. GRB 240411B: Swift/UVOT Detection
  38. EP240417a: YAHPT Optical Upper Limits
  39. GRB240418A: YAHPT Upper Limits
  40. GRB 240419A: VLT/UVES redshift of z = 5.178
  41. GRB 240419A: VLT optical afterglow detection
  42. GRB 240419A: Enhanced Swift-XRT position
  43. Fermi trigger No 735089036: Global MASTER-Net observations report
  44. EP240416a: J-band observations with WINTER
  45. EP240414a: GMG observation
  46. GRB 240419A: Prompt enhanced Swift-XRT position
  47. GRB 240419A: Swift detection of a burst
  48. GRB 240418A: TSHAO Zeiss-1000 optical upper limit
  49. GRB 240418A: NOT optical upper limits
  50. GRB 240418A: Enhanced Swift-XRT position
  51. GRB 240418A: AKO Upper Limit
  52. GRB 240411A: GOTO early optical upper limits
  53. Swift GRB240418.85: Global MASTER-Net observations report
  54. GRB 240418A: Swift detection of a burst
  55. EP240417a: EP-WXT detection of a fast X-ray transient
  56. Fermi GRB 240417A: Global MASTER-Net observations report
  57. LIGO/Virgo/KAGRA S240413p: X-ray upper limits from EP-WXT for the candidate AGN counterpart
  58. EP240416A: Terskol Zeiss-2000 optical upper limit
  59. EP240416A: Khureltogoot optical upper limit
  60. Improved IPN triangulation of GRB 240411A
  61. EP240416a: BOOTES-2/TELMA Optical Upper Limit
  62. EP240414a: GSP detects optical candidate counterpart AT2024gsa
  63. LIGO/Virgo/KAGRA S240413p: DECam GW-MMADS candidates
  64. IceCube-Cascade 240416A: Upper limits from a search for additional neutrino events in IceCube
  65. GRB 240417A: Fermi GBM Final Real-time Localization
  66. EP240414a: Pan-STARRS detects re-brightening of the candidate counterpart AT2024gsa
  67. LIGO/Virgo/KAGRA S240413p: historical ATLAS and ZTF observations of the candidate AGN counterpart
  68. GRB 240415A: Glowbug gamma-ray detection
  69. GRB 240414A: Glowbug gamma-ray detection
  70. LIGO/Virgo/KAGRA S240413p: STEP - T80S Search and Candidate Counterpart Identification
  71. GRB 240415B: GECAM-B detection
  72. EP 240416a: Xinglong and NOT decaying optical counterpart
  73. GRB 240415A: Swift-BAT refined analysis
  74. EP240416A: MASTER optical observations
  75. GRB 240411A: Glowbug gamma-ray detection
  76. GRB 240414A: Swift-BAT refined analysis
  77. EP240416a: Kinder optical counterpart candidate
  78. EP240416a: EP-WXT detection of a fast X-ray transient
  79. GRB 240414A: AbAO optical upprer limit
  80. GRB 240415A: Swift/UVOT Detection
  81. EP240413a: BOOTES-2/TELMA Optical Upper Limit
  82. GRB 240415A: Fermi GBM Observation
  83. GRB 240414A: GAD Observatory, La Spezia, Italy ,upper limit
  84. GRB 240415A: Earliest optical followup with the Kinder observations
  85. GRB 240414A: GMG observation
  86. EP 240414a: BOOTES-4/MET Optical Upper Limits
  87. EP240414a: EP-FXT follow-up observation
  88. GRB 240415A: Enhanced Swift-XRT position
  89. GRB 240415B: Swift ToO observations
  90. GRB 240415B: Swift/BAT-GUANO arcminute localization of a short burst
  91. GRB 240415A: OHP/T193 optical observations
  92. GRB 240415A: optical afterglow detection from the INAF Asiago Observatory
  93. GRB 240415A: SAO RAS optical observations
  94. GRB 240415A: Mondy optical transient detection (photometry correction in GCN 36118 )
  95. GRB 240414A: Fermi GBM Observation
  96. Fermi GRB 240415A: Global MASTER-Net observations report
  97. GRB 240415A: Mondy optical transient detection
  98. GRB 240414A: Photometric observation from 2.2m CAHA
  99. IceCube-240412A: Upper limits from a search for additional neutrino events in IceCube
  100. GRB 240414A: Swift/UVOT Detection

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