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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"
  1. GRB 020124, HST observations of the fading afterglow
  2. IPN triangulation of GRB020708
  3. IPN triangulation of GRB020708
  4. IPN error box for GRB020706
  5. Correction to IPN error box for GRB020706
  6. IPN triangulation of GRB020706
  7. GRB 020705: Optical observations
  8. GRB 020625, optical observations
  9. GRB 020625: Optical observations
  10. GRB 020531: optical photometry of Chandra sources
  11. GRB020625 (=H2081): A Long Burst Localized by HETE
  12. HETE #2081: Optical observations
  13. The Probable Host Galaxy of GRB/XRF 020427
  14. GRB/XRF 020427, detection of an underlying system with the VLT
  15. Gemini IR Detection of AXP 1E 2259+586 Post-Burst
  16. SGR-like X-ray Bursts from AXP 1E 2259+586: follow-up
  17. AXP 1E2259+586: quasi-simultaneous optical observation
  18. AXP 1E2259+586 optical observations
  19. Fading Optical Source in the Field of GRB020531
  20. GRB 020531, INT+WFC deep optical upper limits
  21. SGR-like Bursts from the AXP 1E 2259+586
  22. GRB020405: polarimetric observations
  23. GRB 020531, simultaneous optical observations
  24. GRB 020604, optical observations
  25. GRB 020531/Candidate Redshift
  26. GRB020531: Detection of Candidate Host Galaxy
  27. GRB020531: Second epoch Chandra observations
  28. GRB020604, optical observations
  29. GRB020604, BVRcIc field photometry
  30. GRB020603, BVRcIc field observations
  31. GRB020531, BVRcIc field photometry
  32. GRB020531 Optical observations with TAROT
  33. GRB020531 Optical observations with TAROT
  34. GRB 020418, optical/near-IR observations
  35. GRB 020531, Radio Observations
  36. IPN triangulation of GRB020604
  37. GRB020531 Optical Observations
  38. GRB020531: Observations with the Chandra X-ray Observatory
  39. GRB 020603: Optical Observations
  40. GRB 020603, R-band observation
  41. Correction to IPN triangulation of GRB020603 (possible short/hard burst)
  42. GRB020531: Upper Limit for Detection of Two TAROT Sources
  43. GRB 020603: Optical observations
  44. IPN triangulation of GRB020603 (possible short/hard GRB)
  45. GRB 020531 optical observations with TAROT
  46. Refined IPN error box for GRB020531
  47. GRB020531, optical observations
  48. GRB020531: optical observations
  49. GRB020531, optical observation
  50. GRB020531(=H2042): Optical Observations
  51. IPN triangulation of the short, hard GRB020531 (=H2042)
  52. GRB020531(=H2042): Optical Observations
  53. GRB020531: Optical observations
  54. GRB020531(=H2042): A Short, Hard Burst Localized by HETE
  55. GRB 020525: Optical Observations
  56. GRB020525, optical observations
  57. IPN detection of possible bursts from SGR1806-20
  58. IPN triangulation of GRB020525
  59. XRF 020427: Sudden Ionospheric Disturbance (SID)
  60. HETE Observations of GX354-0 (= MXB1728-34, so-called "Slow
  61. XRF020427: Chandra Identification of a Likely X-ray Counterpart
  62. IPN triangulation of a burst from SGR1806-20
  63. GRB/XRF 020427, Radio Observations
  64. HST detection of the likely host galaxy of GRB 020124
  65. GRB020405 field photometry at ESO
  66. XRF020427: Chandra Observations and Candidate X-ray Counterparts
  67. GRB(XRF) 020427: X-ray afterglow with BeppoSAX
  68. GRB020321 : Optical observations.
  69. GRB020427 BeppoSAX NFI Observation
  70. XRF 020427
  71. GRB020331: Third Epoch and Revised Second Epoch Optical
  72. The end of BSAX GRB activities
  73. GRB 020410, Radio Observations
  74. GRB 020418: Optical observations
  75. GRB 020124: Optical observations
  76. GRB 020418: Optical observations
  77. IPN triangulation of GRB020418
  78. GRB020405: VLT observations of the OT environment
  79. GRB020410: BeppoSAX NFI observations refined analysis
  80. GRB 020409: Optical Observations
  81. Mars Odyssey joins the IPN
  82. IPN triangulation of GRB020413
  83. GRB 020409, 2-nd epoch optical observations at Terskol.
  84. GRB020405: predicted break
  85. GRB 020409: Optical observations
  86. GRB 020409, No Optical Detection to R = 22
  87. GRB020410: second BeppoSAX NFI observation
  88. GRB 020409: No Evidence for an Optical Afterglow
  89. GRB 020409, 2nd epoch optical observations
  90. GRB 020331 Kyoto observation on March 31
  91. GRB 020409
  92. GRB 020409 SARA Observations
  93. GRB "020411"
  94. GRB 020409, No Optical Detection to R = 20
  95. GRB020410: BeppoSAX NFI observation
  96. GRB 020409: Optical observations
  97. April 11 BeppoSAX event (GRB020411) is likely not a GRB
  98. GRB 020410, optical observations
  99. BeppoSAX ALERT: possible GRB020411
  100. GRB 020409, optical observations

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