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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"

35264 results found.

  1. GRB 171020A: Continued RATIR Optical and NIR Observation
  2. GRB 171020A: TAROT Calern observatory optical observations
  3. GRB 171020A: Swift/UVOT Upper Limits
  4. GRB 171020A: NOT spectroscopic redshift
  5. GRB 171020A: Swift-BAT refined analysis
  6. GRB 171020A: RATIR Optical and NIR Observations
  7. GRB 171020A: Swift-XRT refined Analysis
  8. GRB 171020A: Enhanced Swift-XRT position
  9. GRB 171020A: LT observations
  10. GRB 171020A: Correction of alpha in GCN 22031
  11. GRB 171020A: Confirmation of OT fading
  12. GRB 171020A: Mini-MegaTORTORA upper limits on simultaneous optical emission
  13. GRB 171020A: NOT optical afterglow detection
  14. GRB 171020A: Swift detection of a burst
  15. GRB 171011B: Insight-HXMT detection
  16. GRB 171010B: Swift-XRT afterglow detection
  17. GRB 171011B CALET Gamma-Ray Burst Monitor detection
  18. INTEGRAL SPI-ACS observation of IceCube-171015A
  19. GRB 171010A: VLA Observations
  20. GRB 171010A: VLA Detection
  21. GRB 171010A: A detection of a radio source by AMI
  22. GRB 171010A : Optical observations from HCT
  23. GRB 171010A: RATIR Optical and NIR Observations
  24. BAT trigger 778435 is not a GRB.
  25. GRB 171010B: Swift-XRT observations
  26. GRB 171013A: TAROT Calern observatory optical observations
  27. GRB 171013A: Swift detection of a possible burst
  28. GRB 171011A: Swift-BAT refined analysis
  29. Konus-Wind observation of GRB 171011B
  30. GRB 171010A: Swift/UVOT Detection
  31. Konus-Wind observation of GRB 171010A
  32. GRB 171010A: ePESSTO NTT spectroscopic redshift
  33. GRB 171010A: MITSuME Akeno Optical Observation
  34. GRB 171010A: NOT optical observations
  35. GRB 171010B: Fermi GBM detection
  36. IPN Triangulation of GRB 171011B (long/very bright)
  37. GRB 171010B: Swift ToO observations
  38. GRB 171011A: TAROT Calern observatory optical observations
  39. GRB 171010B: Swift detection of a burst
  40. GRB 171011A: MASTER-SAAO optical observations
  41. GRB 171011A: Swift detection of a burst
  42. GRB 171010A: Fermi GBM observation
  43. GRB 171010A: LCO 1m telescope observations
  44. GRB171010A: AstroSat CZTI detection
  45. GRB 171010A: Swift-XRT afterglow detection
  46. GRB 171010A: optical observations
  47. GRB 171010A: OT, spectrum, and possible host galaxy
  48. GRB 171010A: Swift ToO observations
  49. GRB 171010A: Fermi-LAT detection
  50. GRB 171007A: Swift/UVOT Upper Limits
  51. GRB 171007A: Swift-BAT refined analysis
  52. GRB 171007A: Fermi GBM observation
  53. GRB 171007A: Enhanced Swift-XRT position
  54. GRB 171007A: Swift-XRT refined Analysis
  55. GRB 171007A: RATIR Optical and NIR Observations
  56. GRB 171007A: Swift detection of a burst
  57. GRB 171004A: Swift/UVOT Upper Limits
  58. GRB 171004A: Swift-BAT refined analysis
  59. GRB 171004A: Correction to RATIR Astrometry and Photometry
  60. GRB 171004A: Swift-XRT refined Analysis
  61. GRB 171004A: Enhanced Swift-XRT position
  62. GRB 171004A: RATIR Optical and NIR Observations
  63. GRB 170710A: LCO Observations
  64. GRB 171004A: Swift detection of a burst
  65. GRB 171003A: Enhanced Swift-XRT position
  66. Swift Trigger 775946 is a Galactic transient, not GRB 171003
  67. GRB 171003A: LT early optical observations
  68. GRB 171003A: Swift detection of a burst or a Galactic Transient
  69. GRB 171001A: RATIR Optical and NIR Observations
  70. GRB 171001A: Swift-BAT refined analysis
  71. GRB 171001A: Nanshan-0.36m optical afterglow detections
  72. GRB 171001A: Swift-XRT refined Analysis
  73. GRB 171001A: Swift/UVOT Detection
  74. GRB 171001A: IRSF Observation
  75. GRB 171001A: Enhanced Swift-XRT position
  76. GRB 170921A: 15 GHz upper limits from AMI
  77. GRB 170903A: 15 GHz upper limits from AMI
  78. GRB 170906C: 15 GHz upper limits from AMI
  79. GRB 170823A: 15 GHz upper limits from AMI
  80. GRB 170822A: 15 GHz upper limits from AMI
  81. GRB 171001A: Swift detection of a burst
  82. Fermi Gamma-ray Burst Monitor trigger 528508320/170930994 is not a GRB
  83. Fermi Gamma-ray Burst Monitor trigger 528330888/170929011 is not a GRB
  84. 3.6m Devasthal Optical Telescope observations of GRB 170428A
  85. Fermi-GBM GRB misclassifications
  86. GRB 170728B: Kottamia R-band observation
  87. LIGO/Virgo G298048: Summary of Pi of the Sky observations
  88. Konus-Wind observation of GRB 170921B
  89. Correction to GCN Circular 21919: GRB 170921C: Insight-HXMT detection
  90. GRB 170921B: AstroSat CZTI detection
  91. GRB 170906A: Insight-HXMT detection
  92. GRB 170921C: Insight-HXMT detection
  93. IPN Triangulation of GRB 170921B
  94. INTEGRAL SPI-ACS observation of AMON IceCube-170922A
  95. GRB 170921A: RATIR Optical Afterglow Detection and NIR Observations
  96. GRB 170921A: Swift/UVOT Upper Limits
  97. GRB 170921A: Swift-BAT refined analysis
  98. GRB 170918A: Insight-HXMT detection
  99. GRB 170921A: LCO 2m telescope observations
  100. GRB 170921A: NOT optical observations

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