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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"

41646 results found.

  1. HETE 2493: Optical observations
  2. HETE 2493: Optical candidate
  3. GRB 021204: Optical Observations at RIKEN
  4. GRB 021125: Radio Observations
  5. IPN triangulation of GRB021206 (exceptionally bright; annulus only)
  6. GRB 021104, GRB 021112 and GRB 021113 - Milagro GeV/TeV Observations
  7. GRB021201, BVRcIc field photometry
  8. GRB 021201, Radio Observations
  9. GRB 021201: Optical Observations
  10. GRB 021201: BOOTES simultaneous optical observations
  11. IPN triangulation of GRB021201 (short/hard burst, small error box)
  12. GRB021004, late time optical observations
  13. GRB021004 Chandra Observation
  14. IPN detection of continued SGR1900+14 activity
  15. IPN triangulation of GRB021125 (INTEGRAL BURST)
  16. GRB021125 : A long GRB localized by INTEGRAL
  17. IPN confirmation of the reactivation of SGR1900+14
  18. GRB021113, SPI ACS observation
  19. GRB021113: optical observations at Bisei
  20. GRB 021113: Evidence for a Dark Optical Afterglow
  21. GRB 021112, Radio Observations
  22. GRB021112, BVRI field photometry
  23. GRB 021112: Variable Source in R-band search
  24. GRB021112: Optical Observations
  25. GRB021113: Kiso Observations
  26. GRB 021113: Optical observations
  27. GRB 021112: RAPTOR Observations
  28. GRB 021113: Optical Observations
  29. GRB 021113: Optical Observations
  30. GRB 021112: Optical Observations
  31. GRB 021112: R-band search
  32. IPN triangulation of GRB021108 (large error box)
  33. GRB 021016: Optical Observations
  34. IPN triangulation of GRB021109 (annulus)
  35. GRB021004: Near infrared spectroscopy
  36. GRB021104: Optical Observations
  37. Spectropolarimetry of GRB021004
  38. GRB021104: Optical observations
  39. GRB021104: optical observations
  40. GRB021104: possible optical afterglow
  41. Detection of activity from SGR 1900+14 with the RXTE/PCA
  42. GRB021004, late-time optical observations
  43. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  44. IPN triangulation of GRB021025 (annulus)
  45. GRB 021004: optical observations
  46. GRB021004: Optical Observations
  47. GRB 020813; likely host galaxy.
  48. GRB 021008, radio observations
  49. GRB 021016, optical observations
  50. GRB 021004: VRI observations at TNG: possible break
  51. GRB021016, optical observations
  52. GRB 021008, optical observations
  53. GRB021004: Optical Observations
  54. GRB 021004: optical spectroscopy on Oct 11
  55. IPN triangulation of GRB021013 (two small error boxes)
  56. GRB021004: High-resolution optical spectroscopy
  57. XRF 020903: flattening of the optical light curve.
  58. GRB021004, UBVRcIc field photometry update
  59. GRB021004: Optical Observations
  60. GRB 021004 submm observations
  61. GRB021004 Chandra HETG Observations
  62. GRB 021004: Optical/NIR Observations
  63. GRB 021004: Additional V-band Polarimetric Observations
  64. GRB021004: optical observation
  65. GRB 021004: Host Galaxy Star Formation Rate
  66. GRB 021004 submm observations
  67. GRB 021004: WC wind?
  68. GRB021004: NIR and Optical observations
  69. GRB 021004: Optical measurement at OHP
  70. GRB 021004: Optical observations, AUDE network
  71. GRB 021004 - VLA Radio Observations
  72. GRB 021004 - Unusual Radio-to-Submm Spectrum
  73. GRB 021004: optical spectroscopy
  74. XRF 020903 spectrum
  75. GRB 021004: HST/STIS spectroscopic observations
  76. GRB021004: optical observations and predicted break time
  77. GRB021004: BVRc photometry
  78. GRB 021004 redshift
  79. GRB021004 radio observation
  80. GRB021004: restart of optical decay
  81. GRB 021004: Optical Decay
  82. GRB 021004 continued IR fading
  83. HETE fluences for GRB021004
  84. GRB 021004, spectroscopic observations
  85. GRB021004: not fading anymore?
  86. GRB 021004: polarimetric observations
  87. GRB 021004: V-band Polarimetric Observations
  88. GRB021004: Update Bisei photometric data
  89. GRB 021004: Optical Decay
  90. GRB021004, astrometric position
  91. GRB021004, Optical Observations
  92. IRAM Millimeter detection of GRB 021004
  93. GRB 021004: Optical observations at RIKEN
  94. GRB 021004 radio observation
  95. GRB 021004: Optical Observations
  96. GRB021004: continued fading
  97. GRB 021004: Optical Photometry at 1.5 Days
  98. GRB021004, Optical Observations
  99. GRB021004, BVRcIc field photometry
  100. GRB 021004: Optical observations

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