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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

21392 results found.

  1. GRB 231129A: optical upper limit in Mondy observatory
  2. GRB 231129C: Tiled Swift observations
  3. GRB 231129A: Enhanced Swift-XRT position
  4. GRB 231129A: Swift-XRT refined Analysis
  5. GRB 231129B: Tiled Swift observations
  6. GRB 231129A: GECAM-C detection of a long burst
  7. GRB 231129A: INTEGRAL detection of a long GRB
  8. GRB 231129A: Swift detection of a burst
  9. GRB 231123C: Fermi GBM Observation
  10. GRB 231123B: Fermi GBM Observation
  11. GRB 231123B: Swift/BAT-GUANO detection of a burst outside the coded FOV
  12. GRB 231111A: Optical follow-up observations at Terskol, AbAO, Maidanak, Mondy, Assy
  13. GRB 231123C: Insight-HXMT/HE detection
  14. GRB 231123C (short): Glowbug gamma-ray detection
  15. GRB230728A: VIRT optical upper limit
  16. GRB230506B: VIRT optical upper limit
  17. GRB 231123C: Swift/BAT-GUANO detection of a short burst likely outside the coded FOV
  18. GRB 231115A: XMM-Newton observation
  19. GRB 231118A: REM optical afterglow detection
  20. GRB 231122B: AstroSat CZTI detection
  21. GRB 231122B: CALET Gamma-Ray Burst Monitor detection
  22. GRB 231122B: Swift/BAT-GUANO detection of a long burst outside the coded FOV
  23. GRB 231117A: Chandra afterglow detection
  24. GRB 231118A: ATCA detection of radio counterpart
  25. GRB 231117A: Swift/UVOT late time observations
  26. GRB 231117A: Swift-BAT refined analysis
  27. GRB 231118A: GRBAlpha detection
  28. LIGO/Virgo/KAGRA S231118d: Upper limits from Swift/BAT-GUANO
  29. LIGO/Virgo/KAGRA S231118an: Upper limits from Swift/BAT-GUANO
  30. LIGO/Virgo/KAGRA S231114n: Upper limits from Swift/BAT-GUANO
  31. LIGO/Virgo/KAGRA S231113bb: Upper limits from Swift/BAT-GUANO
  32. GRB 231118A: VZLUSAT-2 detection
  33. GRB 231118A: Swift-BAT refined analysis
  34. GRB 231117A: CALET Gamma-Ray Burst Monitor detection
  35. 231118A: Swift-UVOT Detection
  36. GRB231117A: Swift-UVOT detection
  37. GRB 231118A: Fermi GBM observation
  38. GRB 231117A: Swift-XRT refined Analysis
  39. GRB 231118A: Swift-XRT refined Analysis
  40. GRB 231118A: MeerLICHT afterglow detection
  41. GRB 231118A: VLT/X-shooter redshift
  42. GRB 231117A: MAAO 0.7-m telescope optical upper limit
  43. GRB 231117A: GECAM-C detection
  44. GRB 231118A: AstroSat CZTI detection
  45. GRB 231115A: Upper limit from CALET Gamma-Ray Burst Monitor
  46. GRB 231118A: Las Cumbres optical detection
  47. GRB 231118A: LCOGT Optical Observations
  48. GRB 231118A: MASTER OT observation
  49. Swift GRB231118.72: Global MASTER-Net observations report
  50. GRB 231118A: Enhanced Swift-XRT position
  51. GRB 231117A: Kinder observations with Lulin observatory for AT 2023yba without fading in r band
  52. GRB 231118A: Swift-XRT position
  53. GRB 231118A: Skynet Optical Afterglow Discovery
  54. GRB 231118A: Swift detection of a burst
  55. GRB 231117A: ATCA detection of a radio counterpart
  56. GRB 231117A: GRBAlpha detection
  57. GRB 231117A: GIT optical follow-up
  58. GRB 231117A: Keck observations indicate presence of optical afterglow in z~0.3-0.5 galaxy
  59. GRB 231117A: REM optical and NIR early-time observations
  60. GRB 231117A: AKO Optical Upper Limit
  61. GRB 231117A: afterglow candidate detection from Kinder observations with Lulin observatory
  62. Swift GRB 231117A: Global MASTER-Net observations report
  63. GRB 231117A (short): Glowbug gamma-ray detection
  64. GRB 231117A: ATLAS non-detection of an optical counterpart
  65. Konus-Wind detection of GRB 231117A (short/hard)
  66. GRB 231115A: optical observations from INAF observatories
  67. GRB 231117A : MITSuME Akeno optical upper limits
  68. GRB 231117A: AGILE detection of a bright short burst
  69. GRB 231117A: Enhanced Swift-XRT position
  70. GRB 231117A: GOTO optical upper limits
  71. GRB 231117A: AstroSat CZTI detection of a bright short burst
  72. GRB 231117A: Swift detection of a bright short burst
  73. GRB 231111A: Swift/UVOT Detection
  74. GRB 231115A: Swift/BAT-GUANO detection of a short burst
  75. GRB 231115A: Swift-XRT and Swift-UVOT observations
  76. GRB 231115A: Swift ToO observations
  77. GRB 231111A: Swift-BAT refined analysis
  78. GECAM-B observation of a short burst from SGR J1555-5402
  79. SGRJ1555-5402: Swift/BAT-GUANO arcminute localization of a SGR flare
  80. GRB 231110A: CALET Gamma-Ray Burst Monitor detection
  81. GRB 231110A: Swift-BAT refined analysis
  82. GRB231111A: MDM 2.4m Hiltner Telescope Observation
  83. GRB 231111A: Xinglong-2.16m optical observations
  84. GRB 231110A: Swift-UVOT Upper Limits
  85. GRB 231104A: VZLUSAT-2 detection
  86. GRB 231110A: Glowbug gamma-ray detection
  87. GRB 231110A: AstroSat CZTI detection
  88. GRB 231111A NUTTelA-TAO / BSTI Early Measurements
  89. GRB 231111A: Leavitt Observatory optical observations
  90. GRB231111A: Optical follow-up observations with Mephisto
  91. GRB 231111A: Osservatorio Astronomico "Nastro Verde" optical observations with detection of an optical counterpart
  92. GRB 231110A: Terskol Zeiss-2000 optical upper limit
  93. GRB 231111A: Swift-XRT refined Analysis
  94. GRB 231111A: Mondy optical observations
  95. GRB 231111A: GECAM-C detection of a long burst (correction)
  96. GRB 231110A: GECAM-B detection (correction)
  97. GRB 231111A: Enhanced Swift-XRT position
  98. GRB 231111A: GECAM-C detection of a long burst
  99. GRB 231110A: GECAM detection
  100. GRB 231110A: SAO RAS optical observations

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