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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"

6789 results found.

  1. GRB 071013: 3rd TLS Epoch - constraints on variability
  2. GRB 071013: TLS 2nd epoch - Kornienko candidate constant
  3. GRB 071011: Swift-XRT refined analysis
  4. GRB 071011: NAYUTA Optical Observation, correction to GCN6886
  5. GRB 071011, Optical afterglow
  6. GRB 071010: Swift-XRT observation
  7. GRB071008: Swift-XRT observation
  8. GRB 071010: Keck Observations of the Afterglow
  9. GRB 071003: XRT refined analysis
  10. GRB070920A: MAGIC telescope GeV observation
  11. GRB 070810B: further XRT analysis
  12. GRB 071003: Possible rebrightening
  13. GRB 071003: Swift XRT position
  14. GRB 071003 Optical observations
  15. GRB 071001: Swift-XRT Team refined analysis
  16. GRB070925: Swift-XRT Position
  17. GRB 070920B: XRT observations
  18. GRB 070923: Galaxies within BAT localization
  19. INTEGRAL ToO observations of SGR1806-20
  20. GRB 070917: Confirmation of the X-ray afterglow
  21. GRB 070920, Swift-BAT refined analysis
  22. GRB 070917: Swift-XRT observations
  23. GRB 070917: R band observations
  24. GRB 070913: Swift-XRT detection of the possible X-ray afterglow
  25. GRB 070911: PAIRITEL IR Observations
  26. GRB 070911: Swift XRT refined analysis
  27. GRB 070731: Swift/UVOT Upper Limit
  28. IPN Localization of GRB 070821 (long, very bright)
  29. GRB 070810B: XRT refined analysis
  30. A giant outburst from Cygnus X-1 detected by Konus-Wind and Suzaku-WAM
  31. GRB 070810: Swift-XRT Team Refined Analysis
  32. GRB 070809: Swift-XRT refined analysis
  33. GRB 070805: Swift XRT initial analysis.
  34. GRB 070724B: Swift-XRT afterglow confirmation
  35. GRB 070802: Swift-XRT refined analysis
  36. GRB 070802: GROND J band candidate
  37. GRB 070729: Swift-XRT refined analysis
  38. GRB 070729: Magellan NIR Observations
  39. GRB 070724: P60 and Gemini Observations
  40. GRB 070724: Swift-XRT Team refined analysis
  41. GRB 070721A: Swift/XRT refined analysis
  42. GRB 070616: No Evidence for I Band Afterglow
  43. GRB 070714A: Swift XRT refined analysis
  44. GRB070714B: Swift-XRT refined analysis
  45. GRB 070707: Swift-XRT follow-up observations
  46. Swift XRT observation of GRB 070707
  47. GRB 070628: Swift XRT refined analysis
  48. GRB070621: Swift XRT refined analysis
  49. GMRT upper limit of GRB 070610/SWIFT J195509.6+261406 in 610 MHz
  50. GRB 070616: Swift XRT refined circular
  51. SWIFT J195509.6+261406 (GRB 070610): further observations
  52. GRB 070612B: Swift-XRT refined analysis
  53. SWIFT J195509.6+261406 / GRB 070610: SWIFT continued observations
  54. GRB 070610: OPTIMA-Burst detection of continued strong flaring activity
  55. GRB 070610: Swift-XRT refined analysis
  56. GRB 070611: Swift-XRT refined analysis
  57. GRB 070611; Swift-XRT position
  58. GRB 070610; Swift-XRT position
  59. GRB 070529: Swift-XRT refined analysis
  60. GRB 070521: Swift-XRT refined analysis
  61. GRB 070521: Keck imaging
  62. GRB070521: Gemini Observations
  63. GROND upper limits of GRB 070521
  64. GRB 070520B: Swift-XRT refined analysis
  65. GRB 070520A: Swift-XRT refined analysis
  66. GRB 070518: Swift-XRT refined analysis
  67. RHESSI Spectrum of GRB070508
  68. GRB 070508: Swift-XRT refined analysis
  69. GRB070412: MAGIC telescope GeV observation
  70. GRB 070429A: Swift XRT further analysis
  71. GRB 070420: Swift XRT refined analysis
  72. GBR 070419A: Swift/XRT refined analysis
  73. GRB 070419B: Swift XRT refined analysis
  74. GRB 070419A: Optical and IR observations with KANATA
  75. GRB 070418: Optical and IR observations with KANATA
  76. GRB 070406: Swift XRT refined analysis
  77. GRB 070411: Swift-XRT refined analysis
  78. GRB 070406: Swift XRT team further analysis
  79. Suzaku ToO observation of SGR 1806-20
  80. GRB 070406: Astrometrically Refined XRT Position, Unfading Source
  81. GRB 070406: Gemini South Imaging and XRT analysis
  82. GRB 070406: Swift XRT Team analysis - Possible X-ray counterpart
  83. GRB 070406: SARA upper limit
  84. GRB 070330: Swift-XRT refined analysis
  85. Konus-Wind observation of GRB 070328
  86. GRB 070328: Swift/XRT Refined Analysis
  87. GRB070208: optical observations
  88. GRB 070318: Gemini + Magellan spectra
  89. GRB070318: Swift-XRT refined analysis
  90. GRB 070311: Swift-XRT refined analysis
  91. GRB 070125: Chandra X-ray Confirmation of Jet Break
  92. GRB 070125: X-ray light curve analysis
  93. GRB 070306: XRT Team Refined Analysis
  94. GRB 070306: Optical and IR observations with KANATA
  95. GRB070224: Swift-XRT Refined Analysis
  96. GRB 070223: Optical-IR observation with KANATA
  97. GRB 070223: Swift-XRT Refined Analysis
  98. Konus-Wind and Konus-A observations of GRB 070220
  99. GRB 070209: Swift XRT refined analysis
  100. GRB 070219: XRT Refined Analysis

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