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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.

Lucene Examples (click to copy):

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

32083 results found.

  1. GRB 231214A: Swift-BAT refined analysis
  2. GRB 231216A: R-band observations from T120 at Observatoire de Haute-Provence
  3. GRB 231216A: GIT optical upper limit
  4. GRB 231216A: NOT optical upper limits
  5. GRB 231216A: BOOTES-2/TELMA optical upper limit
  6. GRB 231215A: GRBAlpha detection
  7. GRB 231216A: Swift detection of a burst
  8. Konus-Wind detection of GRB 231215A
  9. GRB 231215A: optical afterglow detection from the INAF Asiago Observatory
  10. GRB 231215A: NOT optical observations
  11. GRB 231214A: Swift/UVOT Upper Limits
  12. GRB 231215A: Redshift from OSIRIS+ / GTC
  13. GRB 231205B: VZLUSAT-2 detection
  14. GRB 231204A: VZLUSAT-2 detection
  15. GRB 231215A: GAD Observatory, La Spezia, Italy upper limit;
  16. GRB 231215A: Fermi GBM observation
  17. GRB 231215A: CALET Gamma-Ray Burst Monitor detection
  18. GRB 231215A : OHP/T193 optical afterglow detection
  19. GRB 231215A: Swift/UVOT Detection
  20. GRB 231215A: Swift-XRT refined Analysis
  21. GRB 231215A: BOOTES-4/MET optical detection
  22. GRB 231215A: AKO Optical Upper Limit
  23. GRB 231215A: AGILE detection
  24. GRB 231214A: Fermi GBM observation
  25. Konus-Wind detection of GRB 231210B
  26. ATCA observations of GRB 231210B
  27. GRB 231215A: Enhanced Swift-XRT position
  28. GRB 231214A: REM optical/NIR upper limits
  29. GRB 231215A: GROWTH-India optical follow-up
  30. GRB 231215A : Nanshan/HMT optical observations
  31. GRB 231215A: AstroSat CZTI detection
  32. GRB 231215A : MITSuME Akeno optical afterglow candidate detection
  33. GRB 231214A: Swift-XRT refined Analysis
  34. GRB 231215A: Mondy optical bright afterglow detection
  35. GRB 231214A: AstroSat CZTI detection
  36. GRB 231215C: MASTER OT detection
  37. GRB 231215A: Swift-XRT observations
  38. GRB 231215B: Fermi GBM Final Real-time Localization
  39. GRB 231215A: Swift detection of a burst
  40. GRB 231214A: Fermi-LAT detection
  41. GRB 231214A: Enhanced Swift-XRT position
  42. GRB 231214B: Swift/BAT-GUANO detection of a burst
  43. GRB231214A: BOOTES-6/DPRT optical upper limit
  44. GRB 231214A: Swift detection of a burst
  45. GRB 231214A: Fermi GBM Final Real-time Localization
  46. GRB 231210B: REM optical/NIR upper limits
  47. LIGO/Virgo/KAGRA S231206cc: Upper limits from Swift/BAT-GUANO
  48. LIGO/Virgo/KAGRA S231206ca: Upper limits from Swift/BAT-GUANO
  49. GRB 231212A: GECAM-C detection of a likely short burst
  50. GRB 231210B: MeerLICHT afterglow observations
  51. GRB 231210B: Swift-BAT refined analysis
  52. GRB 231210B: Swift-XRT refined Analysis
  53. GRB 231210B: Enhanced Swift-XRT position
  54. GRB 231210B: VLT/X-shooter redshift
  55. GRB 231210B: detection of the optical counterpart with the LCOGT 40cm telescope at Sutherland Observatory
  56. GRB 231210B: Swift detection of a burst with optical counterpart
  57. IPN triangulation of GRB 231129C
  58. GRB 231210A: Fermi GBM Final Real-time Localization
  59. GRB 231208A: GRBAlpha detection
  60. GRB231205B: Swift/UVOT Upper Limits
  61. GRB 231208A: Glowbug gamma-ray detection
  62. GRB 231208A: AstroSat CZTI detection of a faint burst
  63. IPN triangulation of GRB 231205A
  64. GRB 231205B: Swift-BAT refined analysis
  65. GRB 231205B: 1.3m DFOT Optical upper limit
  66. GRB 231206A: joint location of multiple instruments by ETJASMIN
  67. GRB 231205B: optical upper limit in TSHAOand AbAO
  68. GRB231115A: TURBO Pre-Burst Optical Upper Limits
  69. GRB 231205B: AGILE detection
  70. GRB 231206B: Fermi GBM Final Real-time Localization
  71. GRB 231205B: Ondrejov D50 optical upper limit
  72. GRB 231205B: Swift-XRT refined Analysis
  73. GRB 231205B: REM optical/NIR upper limits
  74. GRB 231129C: ASIM MXGS observation and localization
  75. GRB 231205B: NUTTelA-TAO / BSTI Early Optical Limits
  76. GRB 231205B: r'-band observations from MISTRAL at Observatoire de Haute-Provence
  77. GRB 231206A: GECAM-B detection of a short burst (correction)
  78. GRB 231205B : MITSuME Akeno optical upper limits
  79. GRB 231206A: GECAM-B detection of a short burst
  80. GRB 231205B: Zadko observatory - Gingin optical observations
  81. GRB 231205B: Gaoyazi/GOT optical upper limit
  82. GRB 231205B: Nanshan/HMT optical upper limit
  83. GRB 231205B: GECAM-B detection of a long burst
  84. GRB 231205B: LCOGT Optical Upper Limits
  85. GRB 231205A: DDOTI Upper Limits on the Afterglow
  86. GRB 231205B: Enhanced Swift-XRT position
  87. GRB 231204A: Glowbug gamma-ray detection
  88. GRB 231204A: CALET Gamma-Ray Burst Monitor detection
  89. GRB 231205B: AKO Optical Upper Limit
  90. GRB 231205B: Swift detection of a burst
  91. GRB 231205A: joint location of multiple instruments by ETJASMIN
  92. GRB 231204A: AstroSat CZTI detection
  93. GRB 231205A: GECAM-B detection of a short burst
  94. GRB 231205A: Fermi GBM Final Real-time Localization
  95. LIGO/Virgo/KAGRA S231129ac: Upper limits from Swift/BAT-GUANO
  96. GRB 231203A: Fermi GBM Observation
  97. GRB 231204A: Fermi GBM Final Real-time Localization
  98. GRB 231203A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  99. Konus-Wind detection of GRB 231129C
  100. The Fermi GBM team reports the detection of a likely SHORT GRB

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