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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"

44399 results found.

  1. GRB 111016A: Enhanced Swift-XRT position
  2. GRB 111016A: Swift-XRT observations
  3. GRB 111016A: Swift detection of a burst
  4. GRB 110921A: optical observations
  5. GRB 111008A : miniTAO/ANIR NIR observations
  6. EVLA 22 GHz Detection of GRB 111008A
  7. GRB 111005A: ATCA 18 GHz decay
  8. GRB 111008A: Swift/UVOT Upper Limits
  9. Konus-Wind observation of GRB 111008A
  10. GRB 111008A: IAC80 I-band observations
  11. GRB 111008A: VLT/X-shooter spectroscopy
  12. GRB 111008A: Swift-XRT refined Analysis
  13. GRB 111008A: Gemini spectroscopic redshift
  14. GRB 111008A, GROND observations
  15. GRB 111008A: NOT optical observation
  16. GRB 111008A: Gemini optical counterpart
  17. GRB 111008A: Enhanced Swift-XRT position
  18. GRB 111008A, Swift-BAT refined analysis,
  19. GRB 111008A: Swift detection of a burst
  20. GRB 111005A: ATCA 18 GHz detection
  21. GRB 111005A: ATCA radio upper limit
  22. GRB 111005A : miniTAO/ANIR NIR observations
  23. GRB 111005A: EVLA Observations
  24. GRB 111005A: VLT optical observations
  25. GRB 111005A: GROND NIR observations
  26. GRB 111005A: VLT IR observations
  27. GRB 111005A: Swift-BAT refined analysis
  28. GRB 111005A: bright galaxy in error circle
  29. GRB 111005A: Swift detection of a burst
  30. GRB 111003A: Fermi GBM detection
  31. GRB 110905A / MAXI J1836-194: optical monitoring
  32. GRB 110921A: MITSuME-Akeno Optical photometry
  33. Skynet/Dolomiti observations of GRB 110928A
  34. Skynet observations of GRB 110928A
  35. GRB 110928A: RAPTOR Limits During Gamma-ray Emitting Interval
  36. GRB 110928A: Swift/UVOT Upper Limits
  37. Trigger 504307: Swift detection of MAXI J1836-194
  38. GRB 110928A: Swift-XRT refined Analysis
  39. GRB 110825A: GROND Observations
  40. GRB 110928A: Enhanced Swift-XRT position
  41. GRB 110928A: P60 Observations
  42. GRB 110928A: Further PAIRITEL NIR Observations
  43. GRB 110928A: Swift-BAT refined analysis
  44. GRB 110928A: Swift-XRT observations
  45. GRB 110928A: Swift/UVOT finding chart observation
  46. GRB 110928A: PAIRITEL NIR Observations
  47. GRB 110928A: ROTSE-III Optical Limits
  48. GRB 110928A: Swift detection of a burst
  49. Fermi GBM triggers 110923481, 110924391 and 110925200 are not GRBs
  50. Swift-BAT trigger 503926 is noise
  51. GRB 110924A: Swift detection of a possible burst
  52. GCN for GRB 110921B
  53. GRB 110921A: Swift/UVOT Observations
  54. GRB110918A: Lick Observations
  55. GRB 110921A: NOT observations
  56. GRB 110921A: Fermi GBM observation
  57. GRB 110921A: TNT astrometry
  58. GRB 110921A: Swift-XRT refined Analysis
  59. GRB 110921A, Swift-BAT refined analysis
  60. GRB 110918A: Liverpool Telescope optical observations
  61. GRB 110918A: submm observations from APEX
  62. GRB 110921A: optical observations in Mt. Terskol and Maidanak observatories
  63. GRB 110921A: Enhanced Swift-XRT position
  64. GRB 110921A: MITSuME Akeno Optical Observation
  65. GRB 110921A : TNT optical counterpart candidate
  66. GRB 110918A: Swift-XRT refined Analysis
  67. GRB 110918A: Spectroscopy from GTC
  68. GRB 110921A: MASTER-Net early limit
  69. GRB 110921A: Swift detection of a burst
  70. GRB 110915B : X-ray afterglow confirmation
  71. GRB 110918A: Swift/UVOT Detection of the Optical Counterpart
  72. GRB 110918A: rest-frame energetics in gamma-gays
  73. GRB 110918A optical observation
  74. GRB 110918A: Gemini-N redshift
  75. GRB 110918A: Afterglow Confirmation from PTF
  76. GRB 110918A: GROND detection of the afterglow candidate
  77. GRB 110918A: INT optical detection of Swift candidate afterglow
  78. GRB 110918A: Swift-XRT observations
  79. GRB 110918A: pseudo-z= from prompt emission spectrum
  80. Konus-Wind observation of GRB 110918A
  81. GRB110918A: BOOTES-1 optical limit
  82. MAXI/GSC detection of a short soft X-ray transient
  83. Swift detection of short bursts from PSR J1647-4552
  84. GRB 110915A: Konus-Wind and Swift/BAT joint spectral analysis
  85. IPN triangulation of GRB 110918A (long duration, extremely intense)
  86. GRB 110915B: GROND Observations of the Optical/NIR Afterglow Candidate
  87. GRB 110915A: Swift/UVOT Upper Limits
  88. GRB 110915B: Swift/UVOT Upper Limits
  89. GRB 110915A: GROND Upper limits
  90. GRB 110915A, Swift-BAT refined analysis
  91. GRB 110915A: Swift-XRT refined Analysis
  92. GRB 110915B: Afterglow candidate from OSN
  93. GRB 110915A: Deep Near-IR Limits from Magellan
  94. GRB 110915B: XRT afterglow candidate
  95. GRB 110903A: Suzaku WAM observation of the prompt emission
  96. GRB 110915A: Deep Gemini-South i/z-band imaging
  97. GRB110915A MITSuME Okayama J-band upper-limit
  98. GRB 110915A: MITSuME Okayama and Ishigakijima Optical upper limits
  99. GRB 110915A: NOT observations
  100. GRB 110915A: 1.23m CAHA I-band observations

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