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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"

8474 results found.

  1. Probable GRB in INTEGRAL SPI-ACS
  2. GRB 021112: Evidence for Another Dark Optical Afterglow
  3. XRF 020903 : HST observations
  4. GRB021204: Kiso Observations
  5. GRB 021201 (short/hard), NOT observations
  6. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  7. HETE 2493: Optical observations
  8. HETE 2493: Optical candidate
  9. IPN detection of renewed activity from SGR1806-20
  10. IPN detection of continued SGR1900+14 activity
  11. IPN confirmation of the reactivation of SGR1900+14
  12. IPN detection of possible reactivation of SGR1900+14
  13. GRB 021112: Afterglow or Variable Star?
  14. GRB 021112, Radio Observations
  15. GRB 021112: Variable Source in R-band search
  16. GRB 021113: Optical observations
  17. IPN triangulation of bursts from SGR1900+14, November 1-2, 2002
  18. SGR1900+14 activity, November 2-4, 2002
  19. GRB021104: Candidate present in DSS
  20. GRB 021004: optical spectroscopy
  21. GRB021004: restart of optical decay
  22. GRB021004, Optical Observations
  23. GRB 021004: radio observations
  24. GRB 021004: Kyoto observation
  25. GRB021004: Optical Afterglow
  26. XRF 020903: Supernova
  27. XRF 020903: Optical observations
  28. Second epoch K band imaging of GRB 020819
  29. GRB 020813 : HST observations
  30. Confirming no variability for GRB02081
  31. GRB020819 : Optical observations at KISO
  32. GRB 020819 : OT candidate - confirmation of non variability
  33. GRB 020819: Optical observations
  34. K band observation of GRB 020819
  35. HETE 2275: Optical observations
  36. GRB020813: Fading X-ray Afterglow Observed with Chandra
  37. GRB020812: optical observations
  38. GRB020813(=H2262): Revised Localization with HETE SXC
  39. GRB 020813, radio detection
  40. GRB 020812 : optical afterglow candidate
  41. GRB020812: optical observations
  42. GRB020813, optical observations
  43. GRB020812: possible afterglow candidate
  44. GRB020812: possible afterglow candidate
  45. GRB020813, astrometric position
  46. GRB020813: Fading of Candidate OT
  47. GRB020813: Candidate Optical Afterglow
  48. GRB020801: Candidate OT present in DSS
  49. GRB020801, optical afterglow candidate
  50. GRB 020410: Discovery of Probable OT by HST
  51. GRB 020705: Optical observations
  52. GRB 020625: Optical observations
  53. GRB 020531: optical photometry of Chandra sources
  54. HETE #2081: Optical observations
  55. Gemini IR Detection of AXP 1E 2259+586 Post-Burst
  56. SGR-like X-ray Bursts from AXP 1E 2259+586: follow-up
  57. AXP 1E2259+586: quasi-simultaneous optical observation
  58. AXP 1E2259+586 optical observations
  59. SGR-like Bursts from the AXP 1E 2259+586
  60. GRB 020531/Candidate Redshift
  61. GRB020531: Detection of Candidate Host Galaxy
  62. GRB 020603: Optical observations
  63. GRB 020531 optical observations with TAROT
  64. XRF020427: Chandra Observations and Candidate X-ray Counterparts
  65. GRB(XRF) 020427: X-ray afterglow with BeppoSAX
  66. XRF 020427
  67. GRB020331: Third Epoch and Revised Second Epoch Optical
  68. GRB 020418: Optical observations
  69. GRB 020418: Optical observations
  70. GRB020410: BeppoSAX NFI observations refined analysis
  71. GRB 020409: Optical observations
  72. GRB020406(?), optical observations
  73. GRB020410, optical observations
  74. X-ray afterglow of GRB020321
  75. GRB020331: Confirmation of Afterglow Candidate with Magellan
  76. GRB 020321: Candidate X-ray Counterparts
  77. ASM GRB candidate 020406 refined error box
  78. GRB020331: Optical Observations of Afterglow Candidate
  79. GRB020405: OT observations
  80. GRB 020331: Candidate Optical Afterglow
  81. GRB 020405: Decay index
  82. GRB020405, Radio Observations
  83. GRB020405: VLT spectroscopy
  84. Fading Optical Afterglow and Possible Host Galaxy of GRB 020405
  85. GRB 020405, U-band observations
  86. GRB 020405: Optical afterglow candidate
  87. GRB 020331: NIR Observations
  88. GRB020331 NIR observation at KPNO (re-submission)
  89. GRB02033 NIR observation at KPNO
  90. GRB 020331, NIR observations
  91. GRB 020331: Optical observations
  92. SN 2002ap - peak brightness date (SN/GRB?)
  93. GRB 020322: Optical Observations
  94. GRB020127: Proposed Host Galaxy Detection and Identification of Afterglow
  95. GRB 020321: Optical observations
  96. GRB020322: Candidate Optical Afterglow
  97. GRB 020322: Optical candidate
  98. GRB020321 optical observations
  99. GRB020305: NIR observations
  100. GRB 020305: Optical Observations

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