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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"

26368 results found.

  1. GRB 041006: SARA afterglow observations
  2. GRB041006, optical observation in CrAO
  3. Search for SN light in XRF 040912 with MEGACAM
  4. GRB 041006: BR observations with VATT
  5. GRB 041006: Redshift confirmed
  6. GRB 041006: Radio Observations
  7. GRB 041006 : optical follow-up observation at Lulin Observatory
  8. GRB041006: Optical photometry and spectroscopy at TNG
  9. GRB 041006: presice astrometry
  10. GRB041006, optical I observation
  11. GRB041006 (=HETE3570): optical observations
  12. ROTSE-IIIa Observations of GRB 041006
  13. GRB041006: MASTER optical observations
  14. GRB041006,optical observation
  15. Konus-Wind observation of a series SGR 1806-20 bursts on 041005
  16. GRB041006: Fading of optical afterglow candidate
  17. GRB 041006: Optical afterglow candidate
  18. Bursts from SGR 1806-20: Preliminary INTEGRAL results
  19. XRF 020903: Observations of the Host Galaxy
  20. radio observations, GRB 040924
  21. GRB040929,optical observation
  22. GRB040924,optical observation
  23. GRB040924,optical observation
  24. GRB 040924: detection of possible host galaxy by Subaru
  25. GRB040924: KAIT observations
  26. GRB040924 : Optical candidate observations at Lulin observatory
  27. GRB040924 : Optical candidate observations at Lulin observatory
  28. GRB 040924: Subaru NIR observation
  29. XRF 040912: Radio Observations
  30. XRF 040916: Radio Observations
  31. GRB040912(=H3557): Chandra Candidate X-ray Afterglow
  32. XRF040916: continuing decay of OT
  33. TAROT Observations of GRB 040916 (HETE #3558)
  34. GRB040912(=H3557): Candidate Optical Afterglow
  35. XRF040916, optical observations
  36. XRF 040912, identification of CXO sources
  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. GRB040912 (= H3557): Chandra Observations Scheduled
  43. GRB 040912: Optical Observations
  44. GRB/XRF040912,optical observations
  45. GRB 040912, BVRI observations
  46. Optical observations of field of GRB040912
  47. HETE 3557: Optical observations
  48. GRB040903 - A XRF?
  49. GRB040827: analysis of the XMM-Newton observation
  50. GRB040903, REM near-IR observation
  51. Very bright burst detected from SGR 1806-20
  52. ROTSE-III Rapid Response to possible GRB 040903 (INTEGRAL #1972)
  53. Possible GRB 040903 - further analysis
  54. GRB 040827 - Radio Observations
  55. XMM-Newton Images of GRB 040827
  56. GRB 040827: optical and NIR observations at the VLT
  57. GRB 040827: UKIRT - 2nd epoch K-band imaging
  58. GRB 040827: 2nd epoch of Magellan K-band imaging
  59. GRB 040827: K imaging - no evidence of variability
  60. GRB 040827: Detection of NIR afterglow
  61. GRB040827 XMM-Newton observation
  62. GRB040825A: optical limit before GRB
  63. GRB 040825B: Optical observations
  64. GRB 040827 : Planned XMM-Newton observation
  65. GRB040825B, BVRcIc field photometry
  66. GRB040825A, BVRcIc field photometry
  67. GCN GRB OBSERBATION REPORT
  68. GRB 040825A,optical observations
  69. GRB040825A: optical observations
  70. GRB040825B: optical observations
  71. MASTER: GRB040825b optical observation
  72. GRB 040825: Optical observations
  73. XRF040812: possible afterglow second Chandra observation
  74. GRB 040812: Second epoch CXO Observations
  75. GRB040823,optical observation
  76. XRF040812: GMRT observations
  77. XRF 040812: optical observation at VLT
  78. GRB 040812: Optical counterparts of CXO sources
  79. XRF040812: possible afterglow
  80. CXO observation of GRB 040812
  81. GRB 040812: radio observations
  82. GRB040812, optical/IR observations
  83. GRB 040812: a long GRB detected by INTEGRAL
  84. XRF040701: Optical Observations at ESO
  85. GRB 040730, infrared observations
  86. GRB 040730: a long GRB detected with INTEGRAL
  87. Ongoing activity of SGR 1806-20
  88. GRB040624: optical monitoring at TNG
  89. XRF 040701 - optical observations of the decaying Chandra source
  90. XRF040701: Second-Epoch Chandra Observations
  91. XRF040701: VLA Observations
  92. XRF040701: First-Epoch Chandra Observations
  93. GRB040624, optical observations
  94. GRB040706:observation at University of Miyazaki
  95. Optical Observations of GRB040624
  96. GRB 040624: optical observations at TNG and VLT
  97. MASTER: GRB 040624 optical observation after 0,48d
  98. GRB 040624, optical observations
  99. GRB 040624 - A long GRB detected with INTEGRAL
  100. GRB 030329: Rebrightening of hyperluminal ejecta.

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