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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"

3106 results found.

  1. GRB 090201: Swift-XRT refined analysis
  2. GRB 090201: Swift detection of a burst
  3. GRB 090129: Swift-BAT refined analysis
  4. AXP 1E1547.0-5408: Suzaku WAM detections of the current activity
  5. AXP 1E1547.0-5408: Fermi GBM detection of additional bursts
  6. GRB 090113: LOAO Detection Limits in R, I, z, Y-band
  7. GRB 081230: ROTSE-III Detection of Optical Counterpart
  8. Konus-Wind observation of GRB 081222
  9. GRB 081217: Fermi GBM detection
  10. GRB 081210: Xinglong TNT R band Upper Limits
  11. IPN triangulation of short hard GRB 081209
  12. GRB 081203A: optical observations
  13. Swift-XRT observations of GRB 081203B
  14. Swift-BAT Trigger 334129: possible burst
  15. SGR 1806-20: Fermi GBM detection
  16. GRB 081024: Swift detection of a burst
  17. GRB 081017, Swift-BAT refined analysis
  18. GRB 081016B: ROTSE-III Optical Limits
  19. GRB 081016B: Swift detection of a burst
  20. Swift detection of flare on CC Eri
  21. Detection of flare star Algol in Swift-BAT slew data
  22. Fermi GBM detection of additional bursts from AXP 1E1547.0-5408
  23. GRB 080928: Swift-XRT refined analysis
  24. GRB 080916B: Swift detection of a burst
  25. GRB 080903: optical observations
  26. GRB 080903: Liverpool Telescope observations
  27. GRB 080903: Astrotel-Caucasus optical observations
  28. GRB 080903: Optical afterglow candidate
  29. SGR 0501+4516: Decline in Activity
  30. Konus-Wind observations of new SGR 0501+4516
  31. INTEGRAL ToO Observation of SGR0501+4516
  32. Trigger 321551: Continued Large Flaring of SGR 0501+4516
  33. Swift Trigger 321481: A Large Flare from SGR 0501+4516
  34. GRB080810: optical observations
  35. GRB 080810: Swift/UVOT Refined Analysis
  36. GRB 080810: Liverpool Telescope observations
  37. GRB 080810: D50 optical observation
  38. GRB 080810: Observations from NOT
  39. GRB 080810: ROTSE-III Prompt Detection of Optical Counterpart
  40. GRB 080810: Keck/HIRES Spectroscopy
  41. GRB 080810: Swift detection of a burst with a bright optical afterglow
  42. GRB 080723B: XMM-Newton observation
  43. GRB 080727B: IR photometry
  44. GRB 080723B - Swift-XRT position
  45. GRB 080710: REM afterglow confirmation & brightening
  46. GRB 080707: VLT redshift
  47. GRB 080703: UVOT Follow-Up Observation
  48. GRB 080703: VLT observations of the afterglow
  49. GRB 080703: Swift detection of a burst with optical afterglow
  50. GRB 080703A: ROTSE-III Detection of Optical Counterpart
  51. GRB 080623: Swift XRT prompt analysis
  52. GRB 080613B: GROND Upper Limits
  53. GRB 080605: MASTER VWF 46 s AT observation
  54. GRB 080605: Swift detection of a burst with an optical afterglow
  55. Swift/UVOT observations of GRB080604
  56. GRB 080604: Early Super-LOTIS Observations
  57. GRB080604: confirmation of optical afterglow
  58. GRB 080604: Swift detection of a burst with an optical afterglow
  59. Konus-Wind observation of reactivation of SGR 1627-41
  60. Reactivation of SGR 1627-41
  61. IPN triangulation of bright GRB 080513
  62. GRB 080503: Chandra Observation of X-ray Rebrightening or Flattening
  63. GRB 080503: Late-time Optical rebrightening (possible mini-SN)
  64. GRB 080503: Enhanced Swift-XRT position
  65. GRB 080503: New candidate afterglow/host in Gemini imaging
  66. GRB 080503: Swift detection of a short burst
  67. Swift-BAT trigger 309665 is not a GRB
  68. GRB 080420?: Swift detection of a possible short burst
  69. GRB 080413A, Swift-BAT refined analysis
  70. GRB080330: MAGIC telescope GeV observation
  71. GRB 080405: Swift-BAT refined analysis
  72. GRB 080328: Swift detection of a burst with an optical counterpart
  73. GRB 080320: Early Super-LOTIS Observations
  74. GRB 080319A/B/C: INTEGRAL SPI-ACS light curves available
  75. GRB 080319b light curve by Pi-of-the-Sky
  76. GRB 080319b prompt optical observation by Pi-of-the-Sky
  77. GRB080310: Optical observation by MITSuME telescope
  78. GRB080307: Optical upper limits
  79. GRB 080218B: Swift detection of a burst
  80. GRB080212: Optical afterglow candidate observed by MITSuME Telescope
  81. GRB 080205: Swift/UVOT observations
  82. GRB 080205: Enhanced Swift-XRT position
  83. GRB 080205: KAIT OA detection
  84. GRB 080205: Swift detection of a burst
  85. GRB 080129: GROND detection in all bands, and fading
  86. GRB 080129: GROND detection of the optical/NIR afterglow, and fading
  87. IPN triangulation of GRB080122
  88. GRB 080121: Nearby SDSS galaxies
  89. GRB 080120: Swift-XRT refined analysis
  90. GRB080120: Swift XRT position
  91. GRB 071227: Swift detection of a burst
  92. GRB071020: optical observations
  93. GRB 071122 Swift-XRT refined analysis
  94. GRB 071122: Corrected P60 Coordinates
  95. GRB 071122: P60 Optical Afterglow Candidate
  96. GRB 071122: Swift detection of a burst
  97. GRB 071118, Swift-BAT refined analysis
  98. VLT FORS2 observations of short hard GRB071112B
  99. ATCA radio observations of short hard burst GRB 071112B
  100. GRB 071112C: SARA upper limit

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