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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').
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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. IPN triangulation of GRB150702
  2. GRB 020410: Discovery of Probable OT by HST
  3. GRB 020124, HST observations of the fading afterglow
  4. IPN triangulation of GRB020708
  5. IPN triangulation of GRB020708
  6. IPN error box for GRB020706
  7. Correction to IPN error box for GRB020706
  8. IPN triangulation of GRB020706
  9. GRB 020705: Optical observations
  10. GRB 020625, optical observations
  11. GRB 020625: Optical observations
  12. GRB 020531: optical photometry of Chandra sources
  13. GRB020625 (=H2081): A Long Burst Localized by HETE
  14. HETE #2081: Optical observations
  15. The Probable Host Galaxy of GRB/XRF 020427
  16. GRB/XRF 020427, detection of an underlying system with the VLT
  17. Gemini IR Detection of AXP 1E 2259+586 Post-Burst
  18. SGR-like X-ray Bursts from AXP 1E 2259+586: follow-up
  19. AXP 1E2259+586: quasi-simultaneous optical observation
  20. AXP 1E2259+586 optical observations
  21. Fading Optical Source in the Field of GRB020531
  22. GRB 020531, INT+WFC deep optical upper limits
  23. SGR-like Bursts from the AXP 1E 2259+586
  24. GRB020405: polarimetric observations
  25. GRB 020531, simultaneous optical observations
  26. GRB 020604, optical observations
  27. GRB 020531/Candidate Redshift
  28. GRB020531: Detection of Candidate Host Galaxy
  29. GRB020531: Second epoch Chandra observations
  30. GRB020604, optical observations
  31. GRB020604, BVRcIc field photometry
  32. GRB020603, BVRcIc field observations
  33. GRB020531, BVRcIc field photometry
  34. GRB020531 Optical observations with TAROT
  35. GRB020531 Optical observations with TAROT
  36. GRB 020418, optical/near-IR observations
  37. GRB 020531, Radio Observations
  38. IPN triangulation of GRB020604
  39. GRB020531 Optical Observations
  40. GRB020531: Observations with the Chandra X-ray Observatory
  41. GRB 020603: Optical Observations
  42. GRB 020603, R-band observation
  43. Correction to IPN triangulation of GRB020603 (possible short/hard burst)
  44. GRB020531: Upper Limit for Detection of Two TAROT Sources
  45. GRB 020603: Optical observations
  46. IPN triangulation of GRB020603 (possible short/hard GRB)
  47. GRB 020531 optical observations with TAROT
  48. Refined IPN error box for GRB020531
  49. GRB020531, optical observations
  50. GRB020531: optical observations
  51. GRB020531, optical observation
  52. GRB020531(=H2042): Optical Observations
  53. IPN triangulation of the short, hard GRB020531 (=H2042)
  54. GRB020531(=H2042): Optical Observations
  55. GRB020531: Optical observations
  56. GRB020531(=H2042): A Short, Hard Burst Localized by HETE
  57. GRB 020525: Optical Observations
  58. GRB020525, optical observations
  59. IPN detection of possible bursts from SGR1806-20
  60. IPN triangulation of GRB020525
  61. XRF 020427: Sudden Ionospheric Disturbance (SID)
  62. HETE Observations of GX354-0 (= MXB1728-34, so-called "Slow
  63. XRF020427: Chandra Identification of a Likely X-ray Counterpart
  64. IPN triangulation of a burst from SGR1806-20
  65. GRB/XRF 020427, Radio Observations
  66. HST detection of the likely host galaxy of GRB 020124
  67. GRB020405 field photometry at ESO
  68. XRF020427: Chandra Observations and Candidate X-ray Counterparts
  69. GRB(XRF) 020427: X-ray afterglow with BeppoSAX
  70. GRB020321 : Optical observations.
  71. GRB020427 BeppoSAX NFI Observation
  72. XRF 020427
  73. GRB020331: Third Epoch and Revised Second Epoch Optical
  74. The end of BSAX GRB activities
  75. GRB 020410, Radio Observations
  76. GRB 020418: Optical observations
  77. GRB 020124: Optical observations
  78. GRB 020418: Optical observations
  79. IPN triangulation of GRB020418
  80. GRB020405: VLT observations of the OT environment
  81. GRB020410: BeppoSAX NFI observations refined analysis
  82. GRB 020409: Optical Observations
  83. Mars Odyssey joins the IPN
  84. IPN triangulation of GRB020413
  85. GRB 020409, 2-nd epoch optical observations at Terskol.
  86. GRB020405: predicted break
  87. GRB 020409: Optical observations
  88. GRB 020409, No Optical Detection to R = 22
  89. GRB020410: second BeppoSAX NFI observation
  90. GRB 020409: No Evidence for an Optical Afterglow
  91. GRB 020409, 2nd epoch optical observations
  92. GRB 020331 Kyoto observation on March 31
  93. GRB 020409
  94. GRB 020409 SARA Observations
  95. GRB "020411"
  96. GRB 020409, No Optical Detection to R = 20
  97. GRB020410: BeppoSAX NFI observation
  98. GRB 020409: Optical observations
  99. April 11 BeppoSAX event (GRB020411) is likely not a GRB
  100. GRB 020410, optical observations

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