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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"

31727 results found.

  1. GRB 070913: Swift-XRT detection of the possible X-ray afterglow
  2. GRB 070809: The Swift evidence for the SHB nature of this burst
  3. GRB 070913: Swift-BAT refined analysis
  4. GRB 070913: Corrected BAT position
  5. GRB 070913: SMARTS optical/IR observations
  6. GRB 070911: PAIRITEL IR Observations
  7. GRB 070911: Swift XRT refined analysis
  8. GRB 070911, Swift-BAT refined analysis
  9. IPN search for a GRB associated with TAROT transient on August 31
  10. Intense burst from SGR 1806-20 detected on September 7
  11. GRB 070809: Confirmation of optical transient
  12. Observations of possible TAROT GRB transient near IC 4779
  13. GRB 070810b: Image Subtraction of Multiple Keck Observations
  14. Las Campanas observations of possible TAROT GRB transient near IC
  15. Konus-Wind observation of GRB 070824
  16. Konus-Wind observation of very bright GRB 070821
  17. GRB 070731: Swift/UVOT Upper Limit
  18. GRB 070805: UVOT afterglow candidate retraction
  19. GRB070810b: optical candidate
  20. GRB 070810A: ROTSE-III Refined Analysis
  21. GRB 061110A: redshift confirmed
  22. GRB 070810B : Faulkes Telescope South Observations
  23. GRB 070810A: Continued Keck Imaging
  24. GRB 070810B: Keck spectroscopy of possible host galaxies
  25. GRB070810B: Swift/UVOT Upper Limits
  26. GRB 070810B: XRT refined analysis
  27. GRB 070810B, Swift-BAT refined analysis
  28. GRB 070809: Swift/UVOT Corrected Photometry
  29. Swift Trigger 287421: False trigger due to star tracker loss
  30. GRB 070810A: Swift-BAT refined analysis
  31. GRB 070810B: Xinglong TNT optical Upper Limit
  32. GRB070810B: Optical observations with KANATA
  33. GRB 070809: Swift/UVOT Upper Limits
  34. VLA upper limit on the short hard burst GRB 070729
  35. GRB 070810: Keck redshift and photometry
  36. No radio detection in superAGILE burst 070724B
  37. GRB 070809: Keck Imaging
  38. GRB 070810: Swift-XRT Team Refined Analysis
  39. GRB 070809: Swift-XRT refined analysis
  40. GRB 070810: Swift/UVOT Optical Counterpart
  41. GRB 070809, Swift-BAT refined analysis
  42. GRB 070809: Optical Pre-imaging from Palomar
  43. GRB 070808: Swift/UVOT upper limits
  44. GRB 070809: ROTSE-III Optical Limits
  45. GRB 070808 : Faulkes Telescope South Observations
  46. GCN Swift XRT update position notices and enhanced position circulars
  47. GRB 070808: Swift XRT refined analysis
  48. GRB 070808, Swift-BAT refined analysis
  49. GRB 070808: OPTIMA-Burst optical upper limit
  50. GRB 070808: Xinglong TNT optical Upper Limit
  51. GRB070808: Optical observations with KANATA
  52. GRB 070808: ROTSE-III Optical Limits
  53. GRB061121A: PROMPT Observations
  54. GRB070805 XRT and UVOT afterglow candidate
  55. GRB070612A: Radio upper limit from GMRT
  56. GRB 070721B: correct afterglow position
  57. Swift/UVOT observations of GRB070805
  58. GRB 070805, Swift-BAT refined analysis
  59. GRB 070805: Swift XRT initial analysis.
  60. UVOT observations of SAXJ1810.8-2609
  61. VLA non-detection of GRB 070721B
  62. GRB 070802: REM optical observations
  63. GRB 070724B: Swift-XRT afterglow confirmation
  64. GRB 070802: Swift-XRT refined analysis
  65. GRB070802: Swift/UVOT upper limits
  66. GRB 070802: Confirmation of the optical afterglow
  67. GRB 070802, Swift-BAT refined analysis
  68. GRB 070802: VLT redshift
  69. GRB 070802: refined Swift XRT position
  70. GRB 070802: V-band detection of the candidate afterglow
  71. GRB 070802: LCO I-band candidate
  72. GRB 070802: GROND J band candidate
  73. GRB 070802: LCO optical observations
  74. GRB 070802: Swift detection of a burst
  75. Konus-A observation of GRB 070729
  76. Swift/UVOT detection of GRB070714B
  77. AGILE-ACS position for the SGR 1806-20 July 27 burst
  78. GRB 070729: LCO optical imaging
  79. VLA upper limit on short hard burst GRB 070714B
  80. Intense burst from SGR 1806-20 detected on July 27
  81. GRB070729: Swift/UVOT upper limits
  82. GRB 070729: Swift-XRT refined analysis
  83. GRB 070729, Swift-BAT refined analysis
  84. GRB 070729: Magellan NIR Observations
  85. GRB 070724B: P60 Observations
  86. GRB 070724B: Swift/UVOT Upper limits
  87. GRB070721A: Swift/UVOT Detection of a Weak Afterglow
  88. GRB 070724B: Swift-XRT afterglow likely candidate
  89. GRB 070721A: optical observations
  90. GRB 070724A: further VLT observations
  91. GRB 070724B: Suzaku WAM observation of the prompt emission
  92. Konus-Wind observation of GRB 070724B
  93. GRB 070724B: Analysis of AGILE gamma-ray data
  94. GRB 070724B: Swift-XRT afterglow candidates
  95. Four radio sources in Swift-XRT error box of GRB 070724
  96. GRB 070724: optical observations
  97. GRB070724: Host galaxy redshift
  98. GRB 070724: P60 and Gemini Observations
  99. GRB 060814 - Keck host detection and redshift
  100. GRB 070724: Closer association with DSS source

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