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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"

2744 results found.

  1. GRB080307 BOAO optical afterglow observation - detection of a possible OT
  2. GRB 080307, Swift-BAT refined analysis
  3. GRB 080307, Preliminary Swift-BAT refined analysis
  4. GRB 080307: Swift detection of a burst
  5. VLA possible radio detection of GRB 080229
  6. GRB080229: Possible optical afterglow
  7. GRB 080212: REM refined analysis
  8. GRB 080210: GOND detection in all bands and redshift upper limit
  9. GRB 080130: further Swift XRT observations confirm fading source
  10. Swift/UVOT observations of GRB080130
  11. GRB 080130(?): Swift XRT observation
  12. GRB 080130?: Detection of a possible burst by BATSS
  13. GRB 080123: Early afterglow detection with BATSS (BAT Slew Survey)
  14. GRB 080129: Gemini-South photometry
  15. GRB 080129: Swift XRT position
  16. GRB 080129 (?): UVOT Upper Limits
  17. GRB 080129 (?): Swift detection of a possible burst
  18. IPN triangulation of GRB080122
  19. XRF 080109 / SN 2008D: GMRT radio observation at 1280 MHz
  20. XRB 080109/SN 2008D: Early decline in brightness and change in colors
  21. Bright X-ray transient / possible XRF in NGC 2770: TNG R imaging
  22. Possible XRF in NGC 2770 - NOT observations of the optical counterpart
  23. Further Swift-BAT analysis of GRB 071227
  24. GRB 071227: Swift-XRT refined analysis
  25. GRB 070429B: Possible UVOT Detection of an Optical Afterglow
  26. GRB 071208?: Swift detection of a possible burst
  27. GRB 071129, Swift-BAT refined analysis
  28. Disregard the "GRB 071126" position
  29. GRB 071118, Swift-BAT refined analysis
  30. GRB 071112: Swift detection of a possible burst
  31. Swift/UVOT initial analysis of GRB071109
  32. GRB 071109: further Swift-XRT analysis
  33. GRB 071109: Swift-XRT possible X-ray counterpart
  34. GRB 071104: Swift-XRT Team Refined Analysis
  35. GRB 071104: Possible Swift UVOT Afterglow Candidate
  36. GRB 071028: Swift detection of a burst
  37. GRB 071025: ROTSE-III Refined Analysis
  38. Possible radio detection of GRB 071021 with the VLA
  39. GRB 071021: possible high-z burst
  40. GRB071018: Correction to the title of the GCN 6936
  41. GRB 071018: Possible OT from Xinglong TNT observation
  42. GRB 071010A: Late-time Keck/LRIS photometry - possible host galaxy and jet break
  43. GRB 071018, Swift-BAT refined analysis
  44. GRB 071018?: Swift detection of a possible burst
  45. GRB 071013: 3rd TLS Epoch - constraints on variability
  46. GRB 071013: TLS 2nd epoch - Kornienko candidate constant
  47. GRB 071010B possible optical transient
  48. GRB 070810B: further XRT analysis
  49. GRB 071003: Keck spectroscopy
  50. GRB 071003: Possible rebrightening
  51. GRB 071003: Keck HIRES spectroscopy
  52. GRB 071003: MARGE Observations
  53. GRB070925: Swift-XRT Afterglow confirmation
  54. GRB 070917: Confirmation of the X-ray afterglow
  55. Swift Status and XRT Calibration Uncertainties
  56. GRB 070913: Swift-XRT detection of the possible X-ray afterglow
  57. Observations of possible TAROT GRB transient near IC 4779
  58. Las Campanas observations of possible TAROT GRB transient near IC
  59. Orphan GRB candidate in IC 4779 at TAROT La Silla observatory
  60. Swift observatory off line
  61. GRB 070810A: Continued Keck Imaging
  62. GRB 070810B: Keck spectroscopy of possible host galaxies
  63. GRB 070810B: XRT refined analysis
  64. GRB070810B: Optical observations with KANATA
  65. GRB 070810B: Swift detection of a short burst
  66. GRB 070809: Keck Imaging
  67. GRB 070810: Swift detection of a burst
  68. GCN Swift XRT update position notices and enhanced position circulars
  69. GRB070612A: Radio upper limit from GMRT
  70. GRB 070729: LCO optical imaging
  71. Four radio sources in Swift-XRT error box of GRB 070724
  72. GRB 070721: Swift detection of a possible burst
  73. Swift detection of a possible burst (Trigger 284850)
  74. GRB 070611: VLT observations
  75. GRB 070628: Swift XRT refined analysis
  76. GRB 070628: Swift detection of a possible burst
  77. GRB 070612A: Second Epoch WSRT Radio Observations
  78. GRB 070621: VLT optical observations
  79. GMRT upper limit of GRB 070610/SWIFT J195509.6+261406 in 610 MHz
  80. GRB070612A: Gemini Spectroscopic Redshift
  81. GRB 070616: Swift XRT refined circular
  82. GRB 070612A: Possible WSRT Radio Detection
  83. Swift XRT observations of the INTEGRAL burst GRB070615: Possible
  84. GRB 070612A: P60 Confirmation of Afterglow and An Underlying, Nearby
  85. SWIFT J195509.6+261406 / GRB 070610: SWIFT continued observations
  86. GRB 070612A: SARA detection of possible OT
  87. GRB 070610: SARA upper limit
  88. GRB 070610: Swift-XRT refined analysis
  89. GRB 070611, Swift-BAT refined analysis
  90. GRB 070419A, deep LBT photometry and possible supernova detection
  91. GRB 070529, Swift-BAT refined analysis
  92. GRB 070521 Milagro GeV/TeV Observations
  93. GRB 070521: Subaru observations and possible host detection
  94. GRB 070520A: Subaru Observations
  95. GRB 070517: Gemini optical imaging
  96. GRB 070510: Swift detection of a possible burst
  97. GRB 070508: Multicolor optical observations and possible redshift limit
  98. GRB 070507: Swift detection of a possible cosmic ray shower event or a possible burst
  99. GRB070429B: possible host galaxy detection
  100. GRB 070429A: Swift XRT refined analysis

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