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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"

18485 results found.

  1. GRB021125 : A long GRB localized by INTEGRAL
  2. GRB 021112: Afterglow or Variable Star?
  3. GRB021113: optical observations at Bisei
  4. GRB021112, BVRI field photometry
  5. GRB 021112: Variable Source in R-band search
  6. GRB021112: Optical Observations
  7. GRB 021113: Optical observations
  8. GRB 021112: RAPTOR Observations
  9. GRB021113 (=H2449): A Long GRB Localized by HETE
  10. GRB021112 (=H2448): A Long GRB Localized by HETE
  11. GRB 021016: Optical Observations
  12. GRB021004: Near infrared spectroscopy
  13. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  14. SGR1900+14 activity, November 2-4, 2002
  15. GRB021104: optical observations
  16. Detection of activity from SGR 1900+14 with the RXTE/PCA
  17. IPN triangulation of GRB021027 (single large error box)
  18. GRB 021004: optical observations
  19. GRB021004: Optical Observations
  20. GRB021016(=H2397): A Long GRB Localized by HETE
  21. IPN triangulation of GRB021014 (large error box)
  22. IPN triangulation of GRB021013 (two small error boxes)
  23. XRF 020903: flattening of the optical light curve.
  24. GRB021004, UBVRcIc field photometry update
  25. IPN triangulation of GRB021008 (single error box)
  26. IPN triangulation of GRB021008 (two small error boxes)
  27. GRB021004 Chandra HETG Observations
  28. GRB 021004: Optical/NIR Observations
  29. GRB 021004: Additional V-band Polarimetric Observations
  30. GRB021004: optical observation
  31. GRB 021004: Host Galaxy Star Formation Rate
  32. GRB 021004: WC wind?
  33. GRB021004: NIR and Optical observations
  34. IPN triangulation of GRB021007 (annulus)
  35. XRF 020903 spectrum
  36. GRB021004: BVRc photometry
  37. GRB 021004 redshift
  38. GRB021004 radio observation
  39. HETE fluences for GRB021004
  40. GRB 021004: Optical Photometry at 2.5 Days
  41. GRB 021004: polarimetric observations
  42. GRB 021004: V-band Polarimetric Observations
  43. GRB021004: Update Bisei photometric data
  44. GRB 021004: Optical Decay
  45. GRB 021004 radio observation
  46. GRB 021004: Optical Photometry at 1.5 Days
  47. GRB021004, BVRcIc field photometry
  48. GRB021004: Optical Spectroscopy
  49. GRB 021004 radio search
  50. XRF020903, BVRI field photometry
  51. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  52. XRF020903: TNG and Asiago photometry
  53. XRF 020903: Correction to GCN 1560
  54. XRF 020903: VRI observations
  55. XRF 020903: R band observations
  56. IPN triangulation of GRB020923 (two error boxes)
  57. IPN triangulation of GRB020914 - clarification and additional information
  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. SGR1900+14 burst localized by HETE
  65. GRB020812: negative optical observations
  66. GRB 020812: optical observation at Kyoto University
  67. Second epoch K band imaging of GRB 020819
  68. GRB 020813 : HST observations
  69. GRB 020812: early time optical observation at Ouda Station
  70. GRB020813: Magellan BVRI Photometry
  71. GRB 020819: Optical observations
  72. GRB020819(=H2275): A Long Burst Localized by the HETE WXM and SXC
  73. GRB020813: optical and NIR observations
  74. GRB020813: Fading X-ray Afterglow Observed with Chandra
  75. GRB020813, UBVRI field calibration
  76. Polarimetry of GRB020813: evidence for variability
  77. GRB020812: optical observations
  78. GRB020813: High-Resolution Optical Observations
  79. GRB020812: optical observations
  80. GRB020813, optical observations
  81. GRB020813, astrometric position
  82. GRB020813(=H2262): A Long, Bright Burst Localized by HETE in Near-Real Time
  83. GRB 020812 optical observation
  84. GRB020812(=H2257): A Long Burst Localized by HETE in Near-Real Time
  85. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  86. HST Imaging of the Host of GRB 011121
  87. GRB020801, optical afterglow candidate
  88. GRB020331: Late-time Optical Light Curve (re-submission)
  89. GRB020331: Late-time Optical Light Curve
  90. IPN triangulation of GRB020714
  91. IPN triangulation of GRB150702
  92. GRB 020410: Discovery of Probable OT by HST
  93. IPN triangulation of GRB020708
  94. GRB 020705: Optical observations
  95. GRB 020625, optical observations
  96. GRB 020625: Optical observations
  97. GRB 020531: optical photometry of Chandra sources
  98. GRB020625 (=H2081): A Long Burst Localized by HETE
  99. The Probable Host Galaxy of GRB/XRF 020427
  100. GRB/XRF 020427, detection of an underlying system with the VLT

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