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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"

8477 results found.

  1. GRB 070802: REM optical observations
  2. GRB 070724B: Swift-XRT afterglow confirmation
  3. GRB 070802: VLT redshift
  4. GRB 070802: V-band detection of the candidate afterglow
  5. GRB 070802: LCO I-band candidate
  6. GRB 070802: GROND J band candidate
  7. GRB 070802: Swift detection of a burst
  8. AGILE-ACS position for the SGR 1806-20 July 27 burst
  9. Intense burst from SGR 1806-20 detected on July 27
  10. GRB 070729: Swift detection of a short hard burst
  11. GRB 070724B: Swift/UVOT Upper limits
  12. GRB 070724B: Swift-XRT afterglow likely candidate
  13. GRB 070724: Pre-Imaging Shows a Source in the XRT Error Circle
  14. GRB 070724: Swift detection of a burst
  15. GRB 070721B : Faulkes Telescope South observations
  16. GRB070721B: A bright UVOT candidate
  17. GRB 070721B: Swift detection of a burst
  18. GRB 070714B: confirmation of optical afterglow
  19. GRB070714B: Swift-XRT refined analysis
  20. GRB 070714b ("Bastille"): Optical Pre-Imaging (Clarification)
  21. SN 2007bg - off-axis GRB?
  22. GRB 070707: VLT observations
  23. GRB 070707: A long GRB detected by INTEGRAL
  24. GRB 070707: A long GRB detected by INTEGRAL
  25. GRB 070429B: NIR Observations
  26. GRB 070704: Correction to GCN Circ 6594
  27. GRB 070704: Swift detection of a burst
  28. Swift UVOT Observations of GRB 070628
  29. GRB 070616: Suzaku/WAM observation of the prompt emission
  30. GRB 070612A: Second Epoch WSRT Radio Observations
  31. Keck Laser Guide Star Adaptive Optics Imaging of GRB 070621
  32. GRB 070621: Swift detection of a burst
  33. GRB070616: Optical Observation by MITSuME Akeno
  34. GRB070616: Optical Observation by MITSuME Okayama
  35. GRB 070612A: Possible WSRT Radio Detection
  36. GRB 070616: BTA astrometry and finding chart
  37. GRB 070616: BTA optical observations
  38. GRB 070616: Swift detection of a burst
  39. GRB 070615: A long GRB detected by INTEGRAL
  40. GRB070612A: MITSuME Okayama Observation
  41. GRB 070612A: spectral lag
  42. GRB 070612A: MDM Observations
  43. GRB 070612A: P60 Confirmation of Afterglow and An Underlying, Nearby
  44. GRB 070610: MITSuME OAO optical upper limit
  45. GRB 070610: Swift-XRT refined analysis
  46. GRB 070611: Swift/UVOT Observations
  47. GRB 070611: Swift-XRT refined analysis
  48. GRB 070611: ROTSE-III Detection of Late Rising Optical Counterpart
  49. GRB 070610: Swift-UVOT Upper Limits
  50. GRB 070411: TAROT Calern observatory optical observations
  51. GRB 070531: Swift detection of a burst
  52. GRB 070529: Swift detection of a burst with an optical aterglow
  53. GRB070521: Second Epoch Gemini Imaging
  54. GRB 070521: Keck imaging
  55. GRB070521: Gemini Observations
  56. GRB 070521: Subaru observations and possible host detection
  57. GRB 070520A: Subaru Observations
  58. GRB 070520B: Swift-XRT refined analysis
  59. GRB 070521: Swift detection of a burst
  60. GRB 070520B: Swift detection of a burst
  61. GRB 070520: Swift detection of a burst
  62. GRB 070517: Gemini optical imaging
  63. GRB 070518: Swift detection of a burst with optical afterglow
  64. GRB 070510: Swift detection of a possible burst
  65. GRB 070508: OA fading and tentative redshift
  66. GRB 070509, Swift-BAT refined analysis
  67. GRB 070509: Swift detection of a burst
  68. GRB 070508: TAROT La Silla observatory optical observations
  69. GRB 070508: Swift detection of an intense burst with an optical counterpart
  70. GRB 070507: Swift detection of a possible cosmic ray shower event or a possible burst
  71. GRB 070506: Swift detection of a burst with optical afterglow
  72. GRB 070309: Swift-XRT afterglow confirmation
  73. GRB 070429B: Swift detection of a short burst
  74. GRB 070429: Swift detection of a burst
  75. LT monitoring of GRB070412
  76. GRB 070420: Swift detection of a burst with optical afterglow
  77. GRB 070419A Swift-BAT Refined Analysis
  78. GRB 070419B: Swift XRT refined analysis
  79. GRB 070419A, Optical observations
  80. GRB 070419B optical afterglow candidate
  81. GRB 070419B: optical afterglow candidate
  82. GRB 070419: P60 Confirmation of Optical Afterglow
  83. GRB 070419B: Swift detection of a burst
  84. GRB 070419 optical afterglow candidate
  85. GRB 070419: Swift detection of a burst
  86. Trigger 276045: Swift detection of a possible burst
  87. GRB 070412: Swift-XRT refined position
  88. GRB 070412: Gemini/GMOS afterglow candidate
  89. GRB 070412: IAC80 optical afterglow candidate
  90. GRB 070412: Swift detection of a burst
  91. GRB 070411 : Liverpool Telescope Observations
  92. GRB 070411: ROTSE-III Detection of Optical Counterpart
  93. GRB 070411: Swift detection of a burst with optical afterglow
  94. GRB 070406: Swift XRT team further analysis
  95. Suzaku ToO observation of SGR 1806-20
  96. GRB 070406: Astrometrically Refined XRT Position, Unfading Source
  97. GRB 070406: Correction to the optical candidate in GCN6253
  98. GRB 070406: further analysis of NOT images.
  99. GRB 070406: Swift XRT Team analysis - Possible X-ray counterpart
  100. GRB 070406: NOT observations

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