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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"

41639 results found.

  1. GRB 021201, Radio Observations
  2. GRB 021201: Optical Observations
  3. GRB 021201: BOOTES simultaneous optical observations
  4. IPN triangulation of GRB021201 (short/hard burst, small error box)
  5. GRB021004, late time optical observations
  6. GRB021004 Chandra Observation
  7. IPN detection of continued SGR1900+14 activity
  8. IPN triangulation of GRB021125 (INTEGRAL BURST)
  9. GRB021125 : A long GRB localized by INTEGRAL
  10. IPN confirmation of the reactivation of SGR1900+14
  11. GRB021113, SPI ACS observation
  12. GRB021113: optical observations at Bisei
  13. GRB 021113: Evidence for a Dark Optical Afterglow
  14. GRB 021112, Radio Observations
  15. GRB021112, BVRI field photometry
  16. GRB 021112: Variable Source in R-band search
  17. GRB021112: Optical Observations
  18. GRB021113: Kiso Observations
  19. GRB 021113: Optical observations
  20. GRB 021112: RAPTOR Observations
  21. GRB 021113: Optical Observations
  22. GRB 021113: Optical Observations
  23. GRB 021112: Optical Observations
  24. GRB 021112: R-band search
  25. IPN triangulation of GRB021108 (large error box)
  26. GRB 021016: Optical Observations
  27. IPN triangulation of GRB021109 (annulus)
  28. GRB021004: Near infrared spectroscopy
  29. GRB021104: Optical Observations
  30. Spectropolarimetry of GRB021004
  31. GRB021104: Optical observations
  32. GRB021104: optical observations
  33. GRB021104: possible optical afterglow
  34. Detection of activity from SGR 1900+14 with the RXTE/PCA
  35. GRB021004, late-time optical observations
  36. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  37. IPN triangulation of GRB021025 (annulus)
  38. GRB 021004: optical observations
  39. GRB021004: Optical Observations
  40. GRB 020813; likely host galaxy.
  41. GRB 021008, radio observations
  42. GRB 021016, optical observations
  43. GRB 021004: VRI observations at TNG: possible break
  44. GRB021016, optical observations
  45. GRB 021008, optical observations
  46. GRB021004: Optical Observations
  47. GRB 021004: optical spectroscopy on Oct 11
  48. IPN triangulation of GRB021013 (two small error boxes)
  49. GRB021004: High-resolution optical spectroscopy
  50. XRF 020903: flattening of the optical light curve.
  51. GRB021004, UBVRcIc field photometry update
  52. GRB021004: Optical Observations
  53. GRB 021004 submm observations
  54. GRB021004 Chandra HETG Observations
  55. GRB 021004: Optical/NIR Observations
  56. GRB 021004: Additional V-band Polarimetric Observations
  57. GRB021004: optical observation
  58. GRB 021004: Host Galaxy Star Formation Rate
  59. GRB 021004 submm observations
  60. GRB 021004: WC wind?
  61. GRB021004: NIR and Optical observations
  62. GRB 021004: Optical measurement at OHP
  63. GRB 021004: Optical observations, AUDE network
  64. GRB 021004 - VLA Radio Observations
  65. GRB 021004 - Unusual Radio-to-Submm Spectrum
  66. GRB 021004: optical spectroscopy
  67. XRF 020903 spectrum
  68. GRB 021004: HST/STIS spectroscopic observations
  69. GRB021004: optical observations and predicted break time
  70. GRB021004: BVRc photometry
  71. GRB 021004 redshift
  72. GRB021004 radio observation
  73. GRB021004: restart of optical decay
  74. GRB 021004: Optical Decay
  75. GRB 021004 continued IR fading
  76. HETE fluences for GRB021004
  77. GRB 021004, spectroscopic observations
  78. GRB021004: not fading anymore?
  79. GRB 021004: polarimetric observations
  80. GRB 021004: V-band Polarimetric Observations
  81. GRB021004: Update Bisei photometric data
  82. GRB 021004: Optical Decay
  83. GRB021004, astrometric position
  84. GRB021004, Optical Observations
  85. IRAM Millimeter detection of GRB 021004
  86. GRB 021004: Optical observations at RIKEN
  87. GRB 021004 radio observation
  88. GRB 021004: Optical Observations
  89. GRB021004: continued fading
  90. GRB 021004: Optical Photometry at 1.5 Days
  91. GRB021004, Optical Observations
  92. GRB021004, BVRcIc field photometry
  93. GRB 021004: Optical observations
  94. GRB 021004: optical counterpart
  95. GRB 021004, optical observations
  96. GRB021004: Optical Spectroscopy
  97. GRB 021004: Optical Observations
  98. GRB 021004, SPM optical observations
  99. GRB 021004, optical observations
  100. GRB 021004 radio search

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