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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"

28103 results found.

  1. GRB021211: APO optical observations
  2. IPN detection of continued activity from SGR1806-20
  3. GRB 021211, optical observations
  4. GRB 021211: CTIO observations
  5. GRB021211: Measurement of Early Time Afterglow
  6. VLT spectrum of GRB 021211
  7. GRB 021211: early break in light curve
  8. GRB021211: Optical observations in CrAO
  9. GRB 021211, IR observations
  10. GRB 021211, optical observations
  11. GRB021211: Kiso Observations
  12. GRB021204: Kiso Observations
  13. GRB021211: Optical observations
  14. GRB 021211, R- and I-band observations
  15. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  16. HETE 2493: Optical observations
  17. HETE 2493: Optical observations
  18. IPN detection of renewed activity from SGR1806-20
  19. GRB021201, BVRcIc field photometry
  20. IPN detection of continued SGR1900+14 activity
  21. GRB021125 : A long GRB localized by INTEGRAL
  22. IPN detection of possible reactivation of SGR1900+14
  23. GRB 021112: Afterglow or Variable Star?
  24. GRB 021113: Evidence for a Dark Optical Afterglow
  25. GRB021112, BVRI field photometry
  26. GRB 021113: Optical observations
  27. GRB021004: Near infrared spectroscopy
  28. GRB021104: optical observations
  29. GRB021104: Candidate present in DSS
  30. GRB021104: possible optical afterglow
  31. Detection of activity from SGR 1900+14 with the RXTE/PCA
  32. GRB021004, late-time optical observations
  33. GRB021004: Optical Observations
  34. GRB 020813; likely host galaxy.
  35. GRB 021016, optical observations
  36. GRB 021008, optical observations
  37. GRB021004: Optical Observations
  38. GRB 021004: optical spectroscopy on Oct 11
  39. GRB021004: High-resolution optical spectroscopy
  40. GRB021004, UBVRcIc field photometry update
  41. GRB021004: Optical Observations
  42. GRB021004 Chandra HETG Observations
  43. GRB021004: optical observation
  44. GRB 021004: WC wind?
  45. GRB 021004: Optical observations, AUDE network
  46. GRB 021004 - VLA Radio Observations
  47. GRB 021004 - Unusual Radio-to-Submm Spectrum
  48. GRB 021004: optical spectroscopy
  49. GRB021004: optical observations and predicted break time
  50. GRB021004: BVRc photometry
  51. GRB 021004 redshift
  52. GRB021004: restart of optical decay
  53. GRB 021004: Optical Decay
  54. GRB 021004, spectroscopic observations
  55. GRB021004: not fading anymore?
  56. GRB 021004: Optical Photometry at 2.5 Days
  57. GRB 021004: polarimetric observations
  58. GRB021004: Update Bisei photometric data
  59. GRB 021004: Optical Decay
  60. GRB021004, astrometric position
  61. GRB021004, Optical Observations
  62. IRAM Millimeter detection of GRB 021004
  63. GRB 021004: Optical observations at RIKEN
  64. GRB021004: continued fading
  65. GRB 021004: Optical Photometry at 1.5 Days
  66. GRB021004, Optical Observations
  67. GRB021004, BVRcIc field photometry
  68. GRB 021004: optical counterpart
  69. GRB 021004: Optical Observations
  70. GRB 021004, SPM optical observations
  71. GRB 021004, optical observations
  72. GRB 021004 radio search
  73. GRB 021004: radio observations
  74. GRB 021004: steepening of the optical decay slope
  75. GRB021004: optical observations at Nyrola
  76. GRB021004: Absorption redshift
  77. GRB 021004: Kyoto observation
  78. GRB021004: Optical Afterglow
  79. XRF 020903: Correction to GCN 1560
  80. Radio Observations of XRF 020903: The Missing Link
  81. XRF 020903: Supernova
  82. GRB 020305: HST/STIS observations
  83. XRF 020903: optical observation at Kyoto
  84. GRB020322 : HST/STIS observations
  85. XRF 020903: Optical observations
  86. IPN detection of a burst from SGR1900+14
  87. XRF 020903, optical observations
  88. GRB020813: High-resolution optical spectroscopy
  89. Second epoch K band imaging of GRB 020819
  90. Confirming no variability for GRB02081
  91. GRB 020819: Optical observations
  92. K band observation of GRB 020819
  93. HETE 2275: Optical observations
  94. GRB020813: Fading X-ray Afterglow Observed with Chandra
  95. GRB 020813: addendum to GCN 1498
  96. GRB020813: optical observations at Bisei
  97. GRB020813: V-band decay slope
  98. Polarimetry of GRB020813: evidence for variability
  99. GRB020813 IRAM millimeter observations
  100. GRB020813(=H2262): Revised Localization with HETE SXC

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