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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"

32543 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. GRB 040924: RTT150 optical observations
  15. GRB 040924, optical follow-up
  16. GRB040924: MASTER: OT decay
  17. IPN triangulation of GRB040924 (H3564)
  18. GRB 040924(=H3564): A Short, Bright GRB Localized in Real Time by HETE
  19. XRF 040912: Radio Observations
  20. XRF 040916: Radio Observations
  21. GRB040912(=H3557): Chandra Candidate X-ray Afterglow
  22. XRF040916: continuing decay of OT
  23. TAROT Observations of GRB 040916 (HETE #3558)
  24. GRB040912(=H3557): Candidate Optical Afterglow
  25. XRF040916, optical observations
  26. XRF040916: Optical Transient Candidate by Subaru
  27. XRF 040912, identification of CXO sources
  28. XRF040916, Ic observations
  29. XRF040916: optical follow-up observations
  30. XRF040912, BVRcIc field calibration
  31. XRF040916, BVRcIc field calibration
  32. GRB040916: Archival optical observations
  33. XRF 040916, optical follow-up
  34. GRB040912(=H3557): Observations with the Chandra X-ray Observatory
  35. GRB040916: Optical observations
  36. ROTSE-IIIb Observations of GRB 040916 (HETE #3558)
  37. GRB040916 (= H3558): A Long XRF Localized by HETE
  38. GRB040912 (= H3557): Chandra Observations Scheduled
  39. GRB 040912, BVRI observations
  40. GRB040912 : Kiso Optical follow-up observation
  41. IBAS GRB Alerts 1978-1980
  42. Optical observations of field of GRB040912
  43. GRB040912 (= H3557): A Long GRB or XRF Localized by HETE
  44. GRB040903 - A XRF?
  45. GRB040827: analysis of the XMM-Newton observation
  46. GRB040903, REM near-IR observation
  47. GRB 040903 - INTEGRAL data analysis
  48. Very bright burst detected from SGR 1806-20
  49. ROTSE-III Rapid Response to possible GRB 040903 (INTEGRAL #1972)
  50. Possible GRB 040903 - further analysis
  51. GRB 040827 - Radio Observations
  52. XMM-Newton Images of GRB 040827
  53. GRB040825A: Optical observations
  54. GRB040825A: Optical observations
  55. GRB 040827: optical and NIR observations at the VLT
  56. GRB 040827: UKIRT - 2nd epoch K-band imaging
  57. GRB 040827: 2nd epoch of Magellan K-band imaging
  58. GRB 040827: K imaging - no evidence of variability
  59. GRB 040827: Detection of NIR afterglow
  60. GRB 040827: Possible detection of optical afterglow
  61. GRB 040827: RTT150 optical observations
  62. MASTER: GRB040827 possible OT
  63. GRB 040825B: Optical observations
  64. GRB040827 optical observations
  65. GRB 040827 - Refined position
  66. GRB040825B, BVRcIc field photometry
  67. GCN GRB OBSERBATION REPORT
  68. GRB040825B: optical observations
  69. GRB040825B (=H3510): An XRF Localized in Real Time by HETE
  70. GRB040825B: Correction to GCN 2657
  71. XRF040812: possible afterglow second Chandra observation
  72. GRB 040812: Second epoch CXO Observations
  73. XRF040812: GMRT observations
  74. XRF 040812: optical observation at VLT
  75. GRB 040812: Optical counterparts of CXO sources
  76. XRF040812: possible afterglow
  77. CXO observation of GRB 040812
  78. IPN/HETE localizations of GRB040810 (=H3489)
  79. GRB 040812: Keck and LCO optical observations
  80. GRB 040812: Keck and LCO observations
  81. GRB 040812: radio observations
  82. GRB040812, optical/IR observations
  83. XRF040701: Optical Observations at ESO
  84. IPN/HETE triangulation of GRB040802 (=H3485)
  85. GRB 040730, infrared observations
  86. GRB 040730: Optical observations
  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: Magellan Spectroscopy of Chandra Source #2 Associated Galaxy
  93. XRF040701: First-Epoch Chandra Observations
  94. GRB040709 J,H-band observations
  95. GRB040624, optical observations
  96. XRF 040701, optical observations
  97. GRB 040624: optical observations
  98. Optical Observations of GRB040624
  99. GRB 040624: optical observations at TNG and VLT
  100. GRB 040624: R-band observations

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