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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"

18291 results found.

  1. GRB041219, BVRcIc field calibration
  2. GRB 041219: Infrared Afterglow Candidate
  3. GRB041218, BVRcIc field calibration
  4. GRB041219: Prompt Optical Observations from ROTSE-IIIb
  5. GRB 041219: PAIRITEL IR Observations, < 3 minutes after trigger
  6. GRB 041217: PROMPT Observations
  7. GRB041217: NIR and optical observations with REM
  8. GRB041217: Infrared Observations
  9. GRB041217: The First GRB Located On-Board Swift
  10. GRB041211: Faulkes Telescope continued optical monitoring
  11. Optical transient (GRB?) in Lynx
  12. GRB041211: RAPTOR observations
  13. GRB041211: Ashra Prototype optical observation
  14. GRB041211, BVRcIc field calibration
  15. GRB041211,optical observation
  16. GRB 041211: Infrared Observations
  17. GRB 041211: KAIT observations
  18. GRB 041211(=H3622): A Long GRB Localized by the HETE WXM and SXC
  19. GRB 040924: Afterglow Color
  20. GRB 041006: GETS Optical Afterglow Observation
  21. GRB 041006: Optical Observations
  22. GRB041006, late-time optical photometry
  23. GRB041006: RTT150 Optical Observations
  24. GRB 041016: BOOTES-2 simultaneous observation
  25. GRB041006: RTT150 Optical Observations
  26. GRB041016,optical observation
  27. GRB 041016: Optical limits
  28. GRB 041016:Optical limit during first minute
  29. GRB 041016: Optical limit
  30. GRB 041015 R band observations
  31. GRB040924, BVRcIc field calibration
  32. GRB041015,optical observation
  33. GRB041006: Fading X-ray Afterglow Observed with Chandra
  34. GRB 041015 - A long GRB detected by INTEGRAL
  35. GRB041006: Optical observations and Potential host galaxy
  36. GRB041006, BVRcIc field calibration
  37. GRB 041006: SARA afterglow observations
  38. GRB041006, optical observation in CrAO
  39. Search for SN light in XRF 040912 with MEGACAM
  40. GRB 041006: BR observations with VATT
  41. GRB041006, optical I observation
  42. ROTSE-IIIa Observations of GRB 041006
  43. GRB041006: MASTER optical observations
  44. GRB041006,optical observation
  45. GRB041006: Fading of optical afterglow candidate
  46. GRB 041006: Optical afterglow candidate
  47. SGR 1806-20 still active
  48. radio observations, GRB 040924
  49. GRB040929,optical observation
  50. GRB040924,optical observation
  51. GRB040924,optical observation
  52. GRB040924: KAIT observations
  53. GRB 040924: Subaru NIR observation
  54. GRB040912(=H3557): Chandra Candidate X-ray Afterglow
  55. XRF040916: continuing decay of OT
  56. TAROT Observations of GRB 040916 (HETE #3558)
  57. GRB040912(=H3557): Candidate Optical Afterglow
  58. XRF040916, optical observations
  59. XRF 040912, identification of CXO sources
  60. XRF040912, BVRcIc field calibration
  61. XRF040916, BVRcIc field calibration
  62. GRB040912(=H3557): Observations with the Chandra X-ray Observatory
  63. GRB040916: Optical observations
  64. GRB 040912: Optical Observations
  65. GRB/XRF040912,optical observations
  66. GRB 040912, BVRI observations
  67. Optical observations of field of GRB040912
  68. HETE 3557: Optical observations
  69. GRB040827: analysis of the XMM-Newton observation
  70. GRB040903, REM near-IR observation
  71. ROTSE-III Rapid Response to possible GRB 040903 (INTEGRAL #1972)
  72. Possible GRB 040903 - further analysis
  73. GRB 040827 - Radio Observations
  74. XMM-Newton Images of GRB 040827
  75. GRB 040827: optical and NIR observations at the VLT
  76. GRB040827 XMM-Newton observation
  77. GRB 040825B: Optical observations
  78. GRB 040827 : Planned XMM-Newton observation
  79. GRB 040827 : peak flux
  80. GRB040825B, BVRcIc field photometry
  81. GRB040825A, BVRcIc field photometry
  82. GCN GRB OBSERBATION REPORT
  83. GRB 040825A,optical observations
  84. GRB040825A: optical observations
  85. GRB040825B: optical observations
  86. GRB040823,optical observation
  87. XRF040812: GMRT observations
  88. XRF 040812: optical observation at VLT
  89. Bursting activity from SGR 1806-20 detected with IBAS
  90. GRB 040812: Keck and LCO optical observations
  91. GRB 040812: Keck and LCO observations
  92. GRB 040812: radio observations
  93. GRB040812, optical/IR observations
  94. GRB 040812: a long GRB detected by INTEGRAL
  95. XRF040701: Optical Observations at ESO
  96. IPN/HETE triangulation of GRB040802 (=H3485)
  97. GRB 040730, infrared observations
  98. GRB 040730: a long GRB detected with INTEGRAL
  99. GRB040624: optical monitoring at TNG
  100. XRF 040701 - optical observations of the decaying Chandra source

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