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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"

36019 results found.

  1. ROTSE-IIIa Observations of GRB 041006
  2. GRB041006, submillimetre observations
  3. GRB041006: MASTER optical observations
  4. GRB 041006: Optical decay
  5. GRB 041006 (=H3570): An X-Ray Rich GRB Localized in Real Time by HETE
  6. GRB 041006 : Optical follow-up observation at KISO
  7. GRB 041006: Finding chart
  8. GRB 041006: Optical afterglow candidate
  9. XRF 020903: Observations of the Host Galaxy (authors)
  10. GRB 040924: Second Epoch WSRT Radio Observations
  11. radio observations, GRB 040924
  12. IBAS Alert 1991. Not a real GRB
  13. GRB040929,optical observation
  14. GRB040924,optical observation
  15. GRB040924, RTT150 optical observation
  16. GRB 040924: detection of possible host galaxy by Subaru
  17. GRB040924, RTT150 optical observation
  18. GRB040924: KAIT observations
  19. GRB040924: Afterglow magnitude at t=17.5hr
  20. GRB 040924: WSRT Radio Observations
  21. GRB 040924: NIR finding chart
  22. GRB040924 : Optical candidate observations at Lulin observatory
  23. GRB040924 : Optical candidate observations at Lulin observatory
  24. GRB 040924: Subaru NIR observation
  25. GRB 040924: RTT150 optical observations
  26. GRB 040924, optical follow-up
  27. IPN triangulation of GRB040924 (H3564)
  28. GRB 040924(=H3564): A Short, Bright GRB Localized in Real Time by HETE
  29. GRB040912(=H3557): Chandra Candidate X-ray Afterglow
  30. XRF040916: continuing decay of OT
  31. TAROT Observations of GRB 040916 (HETE #3558)
  32. XRF040916, optical observations
  33. XRF040916: Optical Transient Candidate by Subaru
  34. GRB040916 optical limits 17 min after GRB
  35. XRF 040912 (=H3557): Spectral and Temporal Properties
  36. XRF040916, Ic observations
  37. XRF040912, BVRcIc field calibration
  38. XRF040916, BVRcIc field calibration
  39. GRB040916: Archival optical observations
  40. GRB040912(=H3557): Observations with the Chandra X-ray Observatory
  41. GRB040916: Optical observations
  42. ROTSE-IIIb Observations of GRB 040916 (HETE #3558)
  43. GRB040912 (= H3557): Chandra Observations Scheduled
  44. GRB 040912: Optical Observations
  45. GRB/XRF040912,optical observations
  46. GRB 040912, BVRI observations
  47. Optical observations of GRB/XRF 040912 = HETE 3557
  48. An intense burst from SGR1806-20
  49. IBAS GRB Alerts 1978-1980
  50. Optical observations of field of GRB040912
  51. GRB040912 (= H3557): A Long GRB or XRF Localized by HETE
  52. GRB 040827: XMM-Newton data
  53. GRB040903 - A XRF?
  54. GRB040827: analysis of the XMM-Newton observation
  55. GRB 040903 - INTEGRAL data analysis
  56. IBAS Alert 1974. Not a real GRB
  57. Very bright burst detected from SGR 1806-20
  58. ROTSE-III Rapid Response to possible GRB 040903 (INTEGRAL #1972)
  59. Possible GRB 040903 - further analysis
  60. Possible GRB 040903 detected with INTEGRAL
  61. GRB 040827 - Radio Observations
  62. XMM-Newton Images of GRB 040827
  63. GRB 040827: optical and NIR observations at the VLT
  64. GRB 040827: UKIRT - 2nd epoch K-band imaging
  65. GRB 040827: 2nd epoch of Magellan K-band imaging
  66. GRB 040827: K imaging - no evidence of variability
  67. GRB 040827: Detection of NIR afterglow
  68. GRB 040827: Possible detection of optical afterglow
  69. GRB 040827: RTT150 optical observations
  70. GRB040825A: optical limit before GRB
  71. GRB 040825B: Optical observations
  72. GRB040827 optical observations
  73. GRB 040827 : Planned XMM-Newton observation
  74. GRB 040827 - Refined position
  75. GRB 040827 : peak flux
  76. GRB 040827 - A long GRB detected by INTEGRAL
  77. GRB040825B, BVRcIc field photometry
  78. GRB040825A, BVRcIc field photometry
  79. GCN GRB OBSERBATION REPORT
  80. GRB 040825A,optical observations
  81. Increase of SGR 1806-20 activity
  82. GRB 040825A: Optical observations.
  83. GRB040825B: Correction to GCN 2657
  84. GRB 040825: Optical observations
  85. GRB 040812: Second epoch CXO Observations
  86. GRB040823,optical observation
  87. Triangulation of GRB 040816 (Konus-Wind - Helicon-Coronas-F)
  88. XRF 040812: optical observation at VLT
  89. GRB 040812: Optical counterparts of CXO sources
  90. XRF040812: possible afterglow
  91. CXO observation of GRB 040812
  92. IPN/HETE localizations of GRB040810 (=H3489)
  93. GRB 040812: Keck and LCO optical observations
  94. GRB 040812: Keck and LCO observations
  95. GRB 040812: radio observations
  96. GRB040812, optical/IR observations
  97. Konus-Wind observation of GRB040810 (=H3489)
  98. GRB 040812: a long GRB detected by INTEGRAL
  99. GRB 040810: Optical observations of a limited region
  100. IPN/HETE triangulation of GRB040802 (=H3485)

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