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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"

25044 results found.

  1. GRB 021004: Additional V-band Polarimetric Observations
  2. GRB021004: optical observation
  3. GRB 021004: Host Galaxy Star Formation Rate
  4. GRB 021004 submm observations
  5. GRB 021004: WC wind?
  6. GRB021004: NIR and Optical observations
  7. GRB 021004: Optical observations, AUDE network
  8. GRB 021004 - VLA Radio Observations
  9. GRB 021004 - Unusual Radio-to-Submm Spectrum
  10. GRB 021004: optical spectroscopy
  11. IPN triangulation of GRB021007 (annulus)
  12. GRB021004: optical observations and predicted break time
  13. GRB021004: BVRc photometry
  14. GRB021004 radio observation
  15. HETE fluences for GRB021004
  16. GRB 021004: Optical Photometry at 2.5 Days
  17. GRB 021004: polarimetric observations
  18. GRB 021004: V-band Polarimetric Observations
  19. GRB021004: Update Bisei photometric data
  20. IRAM Millimeter detection of GRB 021004
  21. GRB 021004 radio observation
  22. GRB 021004: Optical Photometry at 1.5 Days
  23. GRB021004, BVRcIc field photometry
  24. GRB021004: Optical Spectroscopy
  25. GRB 021004 radio search
  26. XRF020903, BVRI field photometry
  27. XRF020903: TNG and Asiago photometry
  28. GRB 020903: Optical observations at RIKEN
  29. XRF 020903: Correction to GCN 1560
  30. XRF 020903: VRI observations
  31. XRF 020903: R band observations
  32. XRF 020903: Archival Optical Images
  33. Radio Observations of XRF 020903: The Missing Link
  34. XRF 020903: Supernova
  35. IPN triangulation of GRB020923 (two error boxes)
  36. IPN triangulation of GRB020914B
  37. IPN triangulation of GRB020911 (2 large error boxes)
  38. GRB 020305: HST/STIS observations
  39. Confirmation of IPN error box for GRB020910
  40. IPN triangulation of GRB020910
  41. IPN GCN Circulars now to be issued without restriction
  42. Single IPN error box for GRB020904
  43. XRF 020903: optical observation at Kyoto
  44. GRB020322 : HST/STIS observations
  45. XRF 020903: Optical observations
  46. IPN triangulation of GRB020904
  47. INTEGRAL GRBs added to GCN
  48. SGR1900+14 burst localized by HETE
  49. GRB020813: High-resolution optical spectroscopy
  50. GRB020812: negative optical observations
  51. GRB 020812: optical observation at Kyoto University
  52. Second epoch K band imaging of GRB 020819
  53. GRB 020813 : HST observations
  54. GRB 020812: early time optical observation at Ouda Station
  55. GRB020813: Magellan BVRI Photometry
  56. GRB 020819: Optical observations
  57. K band observation of GRB 020819
  58. GRB020813: optical and NIR observations
  59. GRB020813: Fading X-ray Afterglow Observed with Chandra
  60. GRB020813, UBVRI field calibration
  61. GRB020812: NIR observations
  62. Polarimetry of GRB020813: evidence for variability
  63. GRB020813 IRAM millimeter observations
  64. GRB020812: optical observations
  65. GRB020813: High-Resolution Optical Observations
  66. GRB 020812: optical observation at Bisei
  67. GRB020813: Early Time Magnitude
  68. Millimeter observation of GRB 020813
  69. GRB020812: optical observations
  70. GRB 020813 : KISO multiband optical observations
  71. GRB020813, optical observations
  72. IPN error box for GRB020813
  73. GRB020813, astrometric position
  74. Spectropolarimetry of GRB 020813
  75. GRB 020812 optical observation
  76. GRB020812(=H2257): A Long Burst Localized by HETE in Near-Real Time
  77. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  78. HST Imaging of the Host of GRB 011121
  79. GRB020801, optical afterglow candidate
  80. GRB020331: Late-time Optical Light Curve (re-submission)
  81. GRB020331: Late-time Optical Light Curve
  82. IPN triangulation of GRB020714
  83. IPN triangulation of GRB020715 (=GRB150702)
  84. IPN triangulation of GRB020714
  85. IPN triangulation of GRB150702
  86. GRB 020410: Discovery of Probable OT by HST
  87. GRB 020124, HST observations of the fading afterglow
  88. IPN triangulation of GRB020708
  89. IPN triangulation of GRB020708
  90. Correction to IPN error box for GRB020706
  91. IPN triangulation of GRB020706
  92. GRB 020705: Optical observations
  93. GRB 020625, optical observations
  94. GRB 020625: Optical observations
  95. GRB 020531: optical photometry of Chandra sources
  96. GRB020625 (=H2081): A Long Burst Localized by HETE
  97. The Probable Host Galaxy of GRB/XRF 020427
  98. GRB/XRF 020427, detection of an underlying system with the VLT
  99. Gemini IR Detection of AXP 1E 2259+586 Post-Burst
  100. AXP 1E2259+586 optical observations

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