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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"

28051 results found.

  1. Bursts from SGR 1806-20: Preliminary INTEGRAL results
  2. XRF 020903: Observations of the Host Galaxy
  3. radio observations, GRB 040924
  4. GRB040929,optical observation
  5. GRB040924,optical observation
  6. GRB040924,optical observation
  7. GRB 040924: detection of possible host galaxy by Subaru
  8. GRB040924: KAIT observations
  9. GRB040924 : Optical candidate observations at Lulin observatory
  10. GRB040924 : Optical candidate observations at Lulin observatory
  11. GRB 040924: Subaru NIR observation
  12. XRF 040912: Radio Observations
  13. XRF 040916: Radio Observations
  14. GRB040912(=H3557): Chandra Candidate X-ray Afterglow
  15. XRF040916: continuing decay of OT
  16. TAROT Observations of GRB 040916 (HETE #3558)
  17. GRB040912(=H3557): Candidate Optical Afterglow
  18. XRF040916, optical observations
  19. XRF 040912, identification of CXO sources
  20. XRF040912, BVRcIc field calibration
  21. XRF040916, BVRcIc field calibration
  22. GRB040916: Archival optical observations
  23. GRB040912(=H3557): Observations with the Chandra X-ray Observatory
  24. GRB040916: Optical observations
  25. GRB040912 (= H3557): Chandra Observations Scheduled
  26. GRB 040912: Optical Observations
  27. GRB/XRF040912,optical observations
  28. GRB 040912, BVRI observations
  29. Optical observations of field of GRB040912
  30. HETE 3557: Optical observations
  31. GRB040903 - A XRF?
  32. GRB040827: analysis of the XMM-Newton observation
  33. GRB040903, REM near-IR observation
  34. Very bright burst detected from SGR 1806-20
  35. ROTSE-III Rapid Response to possible GRB 040903 (INTEGRAL #1972)
  36. Possible GRB 040903 - further analysis
  37. GRB 040827 - Radio Observations
  38. XMM-Newton Images of GRB 040827
  39. GRB 040827: optical and NIR observations at the VLT
  40. GRB 040827: UKIRT - 2nd epoch K-band imaging
  41. GRB 040827: 2nd epoch of Magellan K-band imaging
  42. GRB 040827: K imaging - no evidence of variability
  43. GRB 040827: Detection of NIR afterglow
  44. GRB040827 XMM-Newton observation
  45. GRB040825A: optical limit before GRB
  46. GRB 040825B: Optical observations
  47. GRB 040827 : Planned XMM-Newton observation
  48. GRB040825B, BVRcIc field photometry
  49. GRB040825A, BVRcIc field photometry
  50. GCN GRB OBSERBATION REPORT
  51. GRB 040825A,optical observations
  52. GRB040825A: optical observations
  53. GRB040825B: optical observations
  54. MASTER: GRB040825b optical observation
  55. GRB 040825: Optical observations
  56. XRF040812: possible afterglow second Chandra observation
  57. GRB 040812: Second epoch CXO Observations
  58. GRB040823,optical observation
  59. XRF040812: GMRT observations
  60. XRF 040812: optical observation at VLT
  61. GRB 040812: Optical counterparts of CXO sources
  62. XRF040812: possible afterglow
  63. CXO observation of GRB 040812
  64. GRB 040812: radio observations
  65. GRB040812, optical/IR observations
  66. GRB 040812: a long GRB detected by INTEGRAL
  67. XRF040701: Optical Observations at ESO
  68. GRB 040730, infrared observations
  69. GRB 040730: a long GRB detected with INTEGRAL
  70. Ongoing activity of SGR 1806-20
  71. GRB040624: optical monitoring at TNG
  72. XRF 040701 - optical observations of the decaying Chandra source
  73. XRF040701: Second-Epoch Chandra Observations
  74. XRF040701: VLA Observations
  75. XRF040701: First-Epoch Chandra Observations
  76. GRB040624, optical observations
  77. GRB040706:observation at University of Miyazaki
  78. Optical Observations of GRB040624
  79. GRB 040624: optical observations at TNG and VLT
  80. MASTER: GRB 040624 optical observation after 0,48d
  81. GRB 040624, optical observations
  82. GRB 040624 - A long GRB detected with INTEGRAL
  83. GRB 030329: Rebrightening of hyperluminal ejecta.
  84. IPN Summary of SGR1806-20 Activity in 2004
  85. SGR 1806-20: no IR variability of the proposed counterparts
  86. MASTER:HETE Alert 3259 (SRG1806-20) optical observation
  87. SGR 1806-20, potential NIR counterpart
  88. GRB 040606: Optical observations
  89. MASTER: HETE Alert 3274 optical observation
  90. Activivty of SGR 1806-20
  91. GRB 040511, very fast decay?
  92. GRB 030324: Detection and Color of Host Galaxy
  93. GRB 040511: NIR observations with REM
  94. GRB040511: Candidate optical/NIR afterglow
  95. GRB 040511: ROTSE-III Rapid Optical Upper Limits
  96. GRB 040511: Second Epoch Optical Observations
  97. GRB 040511: Optical observations
  98. GRB 040511: Optical Observations
  99. GRB040511: Optical Observations
  100. GRB040511: Optical Observations

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