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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"

28054 results found.

  1. Konus-Wind observation of a series SGR 1806-20 bursts on 041005
  2. GRB041006: Fading of optical afterglow candidate
  3. GRB 041006: Optical afterglow candidate
  4. Bursts from SGR 1806-20: Preliminary INTEGRAL results
  5. XRF 020903: Observations of the Host Galaxy
  6. radio observations, GRB 040924
  7. GRB040929,optical observation
  8. GRB040924,optical observation
  9. GRB040924,optical observation
  10. GRB 040924: detection of possible host galaxy by Subaru
  11. GRB040924: KAIT observations
  12. GRB040924 : Optical candidate observations at Lulin observatory
  13. GRB040924 : Optical candidate observations at Lulin observatory
  14. GRB 040924: Subaru NIR observation
  15. XRF 040912: Radio Observations
  16. XRF 040916: Radio Observations
  17. GRB040912(=H3557): Chandra Candidate X-ray Afterglow
  18. XRF040916: continuing decay of OT
  19. TAROT Observations of GRB 040916 (HETE #3558)
  20. GRB040912(=H3557): Candidate Optical Afterglow
  21. XRF040916, optical observations
  22. XRF 040912, identification of CXO sources
  23. XRF040912, BVRcIc field calibration
  24. XRF040916, BVRcIc field calibration
  25. GRB040916: Archival optical observations
  26. GRB040912(=H3557): Observations with the Chandra X-ray Observatory
  27. GRB040916: Optical observations
  28. GRB040912 (= H3557): Chandra Observations Scheduled
  29. GRB 040912: Optical Observations
  30. GRB/XRF040912,optical observations
  31. GRB 040912, BVRI observations
  32. Optical observations of field of GRB040912
  33. HETE 3557: Optical observations
  34. GRB040903 - A XRF?
  35. GRB040827: analysis of the XMM-Newton observation
  36. GRB040903, REM near-IR observation
  37. Very bright burst detected from SGR 1806-20
  38. ROTSE-III Rapid Response to possible GRB 040903 (INTEGRAL #1972)
  39. Possible GRB 040903 - further analysis
  40. GRB 040827 - Radio Observations
  41. XMM-Newton Images of GRB 040827
  42. GRB 040827: optical and NIR observations at the VLT
  43. GRB 040827: UKIRT - 2nd epoch K-band imaging
  44. GRB 040827: 2nd epoch of Magellan K-band imaging
  45. GRB 040827: K imaging - no evidence of variability
  46. GRB 040827: Detection of NIR afterglow
  47. GRB040827 XMM-Newton observation
  48. GRB040825A: optical limit before GRB
  49. GRB 040825B: Optical observations
  50. GRB 040827 : Planned XMM-Newton observation
  51. GRB040825B, BVRcIc field photometry
  52. GRB040825A, BVRcIc field photometry
  53. GCN GRB OBSERBATION REPORT
  54. GRB 040825A,optical observations
  55. GRB040825A: optical observations
  56. GRB040825B: optical observations
  57. MASTER: GRB040825b optical observation
  58. GRB 040825: Optical observations
  59. XRF040812: possible afterglow second Chandra observation
  60. GRB 040812: Second epoch CXO Observations
  61. GRB040823,optical observation
  62. XRF040812: GMRT observations
  63. XRF 040812: optical observation at VLT
  64. GRB 040812: Optical counterparts of CXO sources
  65. XRF040812: possible afterglow
  66. CXO observation of GRB 040812
  67. GRB 040812: radio observations
  68. GRB040812, optical/IR observations
  69. GRB 040812: a long GRB detected by INTEGRAL
  70. XRF040701: Optical Observations at ESO
  71. GRB 040730, infrared observations
  72. GRB 040730: a long GRB detected with INTEGRAL
  73. Ongoing activity of SGR 1806-20
  74. GRB040624: optical monitoring at TNG
  75. XRF 040701 - optical observations of the decaying Chandra source
  76. XRF040701: Second-Epoch Chandra Observations
  77. XRF040701: VLA Observations
  78. XRF040701: First-Epoch Chandra Observations
  79. GRB040624, optical observations
  80. GRB040706:observation at University of Miyazaki
  81. Optical Observations of GRB040624
  82. GRB 040624: optical observations at TNG and VLT
  83. MASTER: GRB 040624 optical observation after 0,48d
  84. GRB 040624, optical observations
  85. GRB 040624 - A long GRB detected with INTEGRAL
  86. GRB 030329: Rebrightening of hyperluminal ejecta.
  87. IPN Summary of SGR1806-20 Activity in 2004
  88. SGR 1806-20: no IR variability of the proposed counterparts
  89. MASTER:HETE Alert 3259 (SRG1806-20) optical observation
  90. SGR 1806-20, potential NIR counterpart
  91. GRB 040606: Optical observations
  92. MASTER: HETE Alert 3274 optical observation
  93. Activivty of SGR 1806-20
  94. GRB 040511, very fast decay?
  95. GRB 030324: Detection and Color of Host Galaxy
  96. GRB 040511: NIR observations with REM
  97. GRB040511: Candidate optical/NIR afterglow
  98. GRB 040511: ROTSE-III Rapid Optical Upper Limits
  99. GRB 040511: Second Epoch Optical Observations
  100. GRB 040511: Optical observations

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