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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"

42597 results found.

  1. Search for SN light in XRF 040912 with MEGACAM
  2. GRB 040916: Afterglow Color at Early Times
  3. GRB 041006 Optical afterglow observations
  4. IBAS GRB Alert # 2010
  5. GRB 041006: BR observations with VATT
  6. GRB 041006: Redshift confirmed
  7. GRB041006: Liverpool Telescope optical observations
  8. GRB 041006: Colour measurement
  9. GRB041006: break in the light curve
  10. GRB 041006: Radio Observations
  11. GRB 041006 : optical follow-up observation at Lulin Observatory
  12. GRB 041006 : Optical follow-up observation at TAROT
  13. GRB041006: Optical photometry and spectroscopy at TNG
  14. GRB 041006: presice astrometry
  15. GRB041006 (= H3570): Chandra Observations In Progress
  16. GRB 041006 : optical observation at Bisei
  17. GRB041006, optical I observation
  18. GRB041006 (=HETE3570): optical observations
  19. ROTSE-IIIa Observations of GRB 041006
  20. GRB041006, optical observation
  21. GRB041006, submillimetre observations
  22. GRB 041006: Optical decay
  23. GRB 041006 (=H3570): An X-Ray Rich GRB Localized in Real Time by HETE
  24. Konus-Wind observation of a series SGR 1806-20 bursts on 041005
  25. GRB041006: Fading of optical afterglow candidate
  26. GRB 041006: Finding chart
  27. GRB 041006: Optical afterglow candidate
  28. Bursts from SGR 1806-20: Preliminary INTEGRAL results
  29. Very strong outburst from SGR 1806-20 detected with INTEGRAL
  30. XRF 020903: Observations of the Host Galaxy (authors)
  31. XRF 020903: Observations of the Host Galaxy
  32. GRB 040924: Second Epoch WSRT Radio Observations
  33. radio observations, GRB 040924
  34. IBAS Alert 1991. Not a real GRB
  35. Konus-Wind and Helicon-Coronas-F observations of GRB040924
  36. GRB040924, RTT150 optical observation
  37. GRB040924,optical observation
  38. GRB 040924: detection of possible host galaxy by Subaru
  39. GRB040924, RTT150 optical observation
  40. GRB040924: KAIT observations
  41. GRB040924: Afterglow magnitude at t=17.5hr
  42. GRB 040924: WSRT Radio Observations
  43. GRB 040924: NIR finding chart
  44. GRB040924 : Optical candidate observations at Lulin observatory
  45. GRB 040924: Subaru NIR observation
  46. GRB040924: Optical afterglow properties
  47. GRB 040924: RTT150 optical observations
  48. GRB 040924, optical follow-up
  49. GRB040924: MASTER: OT decay
  50. IPN triangulation of GRB040924 (H3564)
  51. GRB 040924(=H3564): A Short, Bright GRB Localized in Real Time by HETE
  52. GRB040924 (H3564): Optical afterglow candidate
  53. XRF 040912: Radio Observations
  54. XRF 040916: Radio Observations
  55. GRB040912(=H3557): Chandra Candidate X-ray Afterglow
  56. XRF040916: continuing decay of OT
  57. TAROT Observations of GRB 040916 (HETE #3558)
  58. GRB040912(=H3557): Candidate Optical Afterglow
  59. XRF040916, optical observations
  60. XRF040916: Optical Transient Candidate by Subaru
  61. GRB040916 optical limits 17 min after GRB
  62. XRF 040912, identification of CXO sources
  63. XRF 040912 (=H3557): Spectral and Temporal Properties
  64. XRF040916, Ic observations
  65. XRF040916: optical follow-up observations
  66. XRF040912, BVRcIc field calibration
  67. XRF040916, BVRcIc field calibration
  68. GRB040916: Archival optical observations
  69. XRF 040916, optical follow-up
  70. GRB040912(=H3557): Observations with the Chandra X-ray Observatory
  71. GRB040916: Optical observations
  72. ROTSE-IIIb Observations of GRB 040916 (HETE #3558)
  73. GRB040916 (= H3558): Improved Localization from HETE WXM
  74. GRB040916 (= H3558): A Long XRF Localized by HETE
  75. GRB040912 (= H3557): Chandra Observations Scheduled
  76. GRB 040912: Optical Observations
  77. GRB/XRF040912,optical observations
  78. GRB 040912, BVRI observations
  79. An intense burst from SGR1806-20
  80. GRB040912 : Kiso Optical follow-up observation
  81. IBAS GRB Alerts 1978-1980
  82. Optical observations of field of GRB040912
  83. HETE 3557: Optical observations
  84. GRB040912 (= H3557): A Long GRB or XRF Localized by HETE
  85. GRB 040827: XMM-Newton data
  86. GRB040903 - A XRF?
  87. GRB040827: analysis of the XMM-Newton observation
  88. GRB040903, REM near-IR observation
  89. GRB 040903 - INTEGRAL data analysis
  90. IBAS Alert 1974. Not a real GRB
  91. Very bright burst detected from SGR 1806-20
  92. ROTSE-III Rapid Response to possible GRB 040903 (INTEGRAL #1972)
  93. Possible GRB 040903 detected with INTEGRAL
  94. GRB 040827 - Radio Observations
  95. XMM-Newton Images of GRB 040827
  96. GRB040825A: Optical observations
  97. GRB 040827: optical and NIR observations at the VLT
  98. GRB 040827: UKIRT - 2nd epoch K-band imaging
  99. GRB 040827: 2nd epoch of Magellan K-band imaging
  100. GRB 040827: K imaging - no evidence of variability

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