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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"

18335 results found.

  1. GRB 021211, optical observations
  2. GRB021211: Kiso Observations
  3. GRB 021201, optical observations
  4. GRB021211: Optical observations
  5. GRB 021201 (short/hard), NOT observations
  6. Chandra observation of the IPN error box of GRB021201 (short/hard)
  7. GRB 021211, R- and I-band observations
  8. GRB021211 - Upper limits from recent and historical observations
  9. IPN triangulation of GRB021206 (small error box)
  10. GRB021201, BVRcIc field photometry
  11. GRB 021201: BOOTES simultaneous optical observations
  12. IPN triangulation of GRB021201 (short/hard burst, small error box)
  13. GRB021004, late time optical observations
  14. IPN BURST POSITION
  15. IPN triangulation of GRB021125 (INTEGRAL BURST)
  16. GRB021125 : A long GRB localized by INTEGRAL
  17. GRB 021112: Afterglow or Variable Star?
  18. GRB021113: optical observations at Bisei
  19. GRB 021113: Evidence for a Dark Optical Afterglow
  20. GRB021112, BVRI field photometry
  21. GRB 021112: Variable Source in R-band search
  22. GRB021112: Optical Observations
  23. GRB 021113: Optical observations
  24. GRB 021112: RAPTOR Observations
  25. GRB 021113: Optical Observations
  26. GRB 021016: Optical Observations
  27. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  28. GRB021104: optical observations
  29. Detection of activity from SGR 1900+14 with the RXTE/PCA
  30. GRB 021004: VRI observations at TNG: possible break
  31. IPN triangulation of GRB021014 (large error box)
  32. IPN triangulation of GRB021013 (two small error boxes)
  33. XRF 020903: flattening of the optical light curve.
  34. GRB021004, UBVRcIc field photometry update
  35. GRB 021004: Optical/NIR Observations
  36. GRB 021004: Additional V-band Polarimetric Observations
  37. GRB021004: optical observation
  38. GRB 021004: Host Galaxy Star Formation Rate
  39. GRB 021004: WC wind?
  40. IPN triangulation of GRB021007 (annulus)
  41. GRB021004: BVRc photometry
  42. GRB021004 radio observation
  43. GRB 021004: Optical Photometry at 2.5 Days
  44. GRB 021004: polarimetric observations
  45. GRB 021004: V-band Polarimetric Observations
  46. GRB021004: Update Bisei photometric data
  47. GRB 021004 radio observation
  48. GRB 021004: Optical Photometry at 1.5 Days
  49. GRB021004, BVRcIc field photometry
  50. GRB 021004 radio search
  51. XRF020903, BVRI field photometry
  52. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  53. XRF020903: TNG and Asiago photometry
  54. XRF 020903: Correction to GCN 1560
  55. XRF 020903: VRI observations
  56. XRF 020903: R band observations
  57. IPN triangulation of GRB020923 (two error boxes)
  58. GRB 020305: HST/STIS observations
  59. XRF 020903: optical observation at Kyoto
  60. GRB020322 : HST/STIS observations
  61. XRF 020903: Optical observations
  62. IPN triangulation of GRB020904
  63. INTEGRAL GRBs added to GCN
  64. GRB020812: negative optical observations
  65. GRB 020812: optical observation at Kyoto University
  66. Second epoch K band imaging of GRB 020819
  67. GRB 020813 : HST observations
  68. GRB 020812: early time optical observation at Ouda Station
  69. GRB020813: Magellan BVRI Photometry
  70. GRB 020819: Optical observations
  71. K band observation of GRB 020819
  72. GRB020813: optical and NIR observations
  73. GRB020813: Fading X-ray Afterglow Observed with Chandra
  74. GRB020813, UBVRI field calibration
  75. Polarimetry of GRB020813: evidence for variability
  76. GRB020812: optical observations
  77. GRB020813: High-Resolution Optical Observations
  78. GRB020813: Early Time Magnitude
  79. GRB020812: optical observations
  80. GRB020813, optical observations
  81. GRB020813, astrometric position
  82. GRB 020812 optical observation
  83. GRB020812(=H2257): A Long Burst Localized by HETE in Near-Real Time
  84. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  85. HST Imaging of the Host of GRB 011121
  86. GRB020801, optical afterglow candidate
  87. Further refinement to IPN error box for GRB020531
  88. GRB020331: Late-time Optical Light Curve (re-submission)
  89. GRB020331: Late-time Optical Light Curve
  90. GRB 020410: Discovery of Probable OT by HST
  91. IPN triangulation of GRB020708
  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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