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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"

44652 results found.

  1. Konus-Wind and Helicon-Coronas-F observations of GRB040924
  2. GRB040924,optical observation
  3. GRB040924, RTT150 optical observation
  4. GRB040924,optical observation
  5. GRB 040924: detection of possible host galaxy by Subaru
  6. GRB040924, RTT150 optical observation
  7. GRB040924: KAIT observations
  8. GRB040924: Afterglow magnitude at t=17.5hr
  9. GRB 040924: WSRT Radio Observations
  10. GRB 040924: NIR finding chart
  11. GRB040924 : Optical candidate observations at Lulin observatory
  12. GRB040924 : Optical candidate observations at Lulin observatory
  13. GRB 040924: Subaru NIR observation
  14. GRB040924: Optical afterglow properties
  15. GRB 040924: RTT150 optical observations
  16. GRB 040924, optical follow-up
  17. GRB040924: MASTER: OT decay
  18. GRB040924: MASTER Optical observations
  19. IPN triangulation of GRB040924 (H3564)
  20. GRB 040924(=H3564): A Short, Bright GRB Localized in Real Time by HETE
  21. GRB040924 (H3564): Optical afterglow candidate
  22. XRF 040912: Radio Observations
  23. XRF 040916: Radio Observations
  24. GRB040912(=H3557): Chandra Candidate X-ray Afterglow
  25. XRF040916: continuing decay of OT
  26. TAROT Observations of GRB 040916 (HETE #3558)
  27. GRB040912(=H3557): Candidate Optical Afterglow
  28. XRF040916, optical observations
  29. XRF040916: Optical Transient Candidate by Subaru
  30. GRB040916 optical limits 17 min after GRB
  31. XRF 040912, identification of CXO sources
  32. XRF 040912 (=H3557): Spectral and Temporal Properties
  33. XRF040916, Ic observations
  34. XRF040916: optical follow-up observations
  35. XRF040912, BVRcIc field calibration
  36. XRF040916, BVRcIc field calibration
  37. GRB040916: Archival optical observations
  38. XRF 040916, optical follow-up
  39. GRB040912(=H3557): Observations with the Chandra X-ray Observatory
  40. GRB040916: Optical observations
  41. ROTSE-IIIb Observations of GRB 040916 (HETE #3558)
  42. GRB040916 (= H3558): Improved Localization from HETE WXM
  43. GRB040916 (= H3558): A Long XRF Localized by HETE
  44. GRB040912 (= H3557): Chandra Observations Scheduled
  45. GRB 040912: Optical Observations
  46. GRB/XRF040912,optical observations
  47. GRB 040912, BVRI observations
  48. Optical observations of GRB/XRF 040912 = HETE 3557
  49. An intense burst from SGR1806-20
  50. GRB040912 : Kiso Optical follow-up observation
  51. IBAS GRB Alerts 1978-1980
  52. Optical observations of field of GRB040912
  53. HETE 3557: Optical observations
  54. GRB040912 (= H3557): A Long GRB or XRF Localized by HETE
  55. GRB 040827: XMM-Newton data
  56. GRB040903 - A XRF?
  57. GRB040827: analysis of the XMM-Newton observation
  58. GRB040903, REM near-IR observation
  59. GRB 040903 - INTEGRAL data analysis
  60. IBAS Alert 1974. Not a real GRB
  61. Very bright burst detected from SGR 1806-20
  62. ROTSE-III Rapid Response to possible GRB 040903 (INTEGRAL #1972)
  63. Possible GRB 040903 - further analysis
  64. Possible GRB 040903 detected with INTEGRAL
  65. GRB 040827 - Radio Observations
  66. XMM-Newton Images of GRB 040827
  67. GRB040825A: Optical observations
  68. GRB040825A: Optical observations
  69. GRB 040827: optical and NIR observations at the VLT
  70. GRB 040827: UKIRT - 2nd epoch K-band imaging
  71. GRB 040827: 2nd epoch of Magellan K-band imaging
  72. GRB 040827: K imaging - no evidence of variability
  73. GRB 040827: Detection of NIR afterglow
  74. GRB 040827: Possible detection of optical afterglow
  75. GRB 040827: RTT150 optical observations
  76. GRB040827 XMM-Newton observation
  77. GRB040825A: optical limit before GRB
  78. MASTER: GRB040827 possible OT
  79. GRB 040825B: Optical observations
  80. GRB040827 optical observations
  81. GRB 040827 : Planned XMM-Newton observation
  82. GRB 040827 - Refined position
  83. GRB 040827 : peak flux
  84. GRB 040827 - A long GRB detected by INTEGRAL
  85. GRB040825B, BVRcIc field photometry
  86. GRB040825A, BVRcIc field photometry
  87. GCN GRB OBSERBATION REPORT
  88. GRB 040825A,optical observations
  89. Increase of SGR 1806-20 activity
  90. GRB040825A: optical observations
  91. GRB040825B: optical observations
  92. GRB040825B (=H3510): An XRF Localized in Real Time by HETE
  93. GRB 040825A: Optical observations.
  94. MASTER: GRB040825a optical observation
  95. MASTER: GRB040825b optical observation
  96. GRB040825B: Correction to GCN 2657
  97. GRB 040825: Optical observations
  98. XRF040812: possible afterglow second Chandra observation
  99. GRB 040812: Second epoch CXO Observations
  100. GRB040823,optical observation

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