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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"

41728 results found.

  1. RXTE PCA Observations of SGR1806-20 Region
  2. GRB030329: Subaru Optical Spectroscopy
  3. Triangulation of GRB030715 (single large error box)
  4. Triangulation of GRB030714 (single large error box)
  5. GRB030329: RTT150 optical observations
  6. GRBlog: Compilation of all GCN Circ. data
  7. GRB030706 triangulation (single large error box)
  8. GRB030329, optical observation in May
  9. IPN triangulation of GRB030626 (single large error box)
  10. GRB030329: second XMM-Newton observation
  11. GRB030418: R optical observations
  12. GRB030329 -- RATAN-600 data in April-May
  13. Final IPN error ellipse for GRB021206 (the polarized GRB)
  14. GRB 021206, Radio afterglow candidate
  15. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  16. GRB030329, SPM optical observations (Correction of GCN2075 R band)
  17. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  18. GRB 030528: Optical Observations
  19. GRB 030528: tentative NIR counterpart
  20. GRB 030528, radio observations
  21. GRB030528(=H2724): Observations with the Chandra X-ray Observatory
  22. GRB030329, further radio observations at GMRT
  23. GRB030528, BVRI field photometry
  24. GRB030329, SPM optical observations
  25. GRB030528: Chandra TOO Planned
  26. GRB 030519B: optical observations.
  27. MASTER: optical observation GRB030601
  28. GRB030528(=H2724): Revised SXC Localization
  29. GRB 030329: optical observations
  30. GRB 030329/SN 2003dh: Jitter Episode
  31. GRB 030528, Teramo optical observation
  32. GRB 030528 Bisei optical observation
  33. GRB030528 (H2724): A long GRB localized by HETE
  34. GRB 030329: Correction to GCN 2254
  35. GRB 030329: Optical Observations
  36. GRB 030528: Optical observations at RIKEN
  37. GRB 030416: Optical Observations
  38. GRB 030329: Planned XMM-Newton Observation
  39. GRB030329, Optical observations
  40. GRB 030329/SN 2003dh: Possible increase in brightness
  41. GRB 030329: HST ACS Observations of the Host
  42. GRB 030329 Optical Observations
  43. GRB030329: XMM-Newton observation
  44. GRB 021004: HST observations
  45. GRB030324: Further Observations of the Candidate Optical Afterglow
  46. GRB030519B (=H2716): Peak Fluxes, Fluences, and Energy Spectrum
  47. IPN triangulation of GRB030519B=H2716 (small error box)
  48. GRB 030418: Second Epoch Optical Observations with Magellan
  49. GRB030519B (=H2716): A Long, Bright GRB Localized by the HETE WXM
  50. IPN triangulation of GRB030514 (annulus)
  51. HETE GRB030329, correction to Rc Observations in Loiano
  52. GRB 030329: Optical limit (contemporaneous imaging)
  53. GRB 030501: final TAROT limits
  54. IPN triangulation of GRB030509 (small errror box)
  55. IPN triangulation of GRB030509 - correction
  56. GRB030329: RTT150 optical observations
  57. GRB030329, BVRI photometry
  58. GRB030429, refiend optical brightness
  59. GRB 030329: Optical limit (contemporaneous photography)
  60. GRB030418, BVRcIc field photometry
  61. GRB 030429: Redshift of neighbor galaxy
  62. GRB030429, BVRcIc field photometry
  63. GRB030429: RTT150 optical obs., correction to GCN 2208
  64. GRB 030329: High-Resolution Spectroscopy of the Host
  65. GRB030429 (=H2695): A Long GRB Localized by the HETE WXM and SXC
  66. GRB030418 (=H2686): A Long, X-Ray-Rich GRB Localized by the HETE WXM
  67. XRF030416 (=U10897): An X-Ray Flash Localized by the HETE WXM
  68. GRB030429: RTT150 optical observations, a possible host galaxy
  69. IPN triangulation of GRB030505B (large error box)
  70. GRB030329: RTT150 optical observations and upper limit for a host
  71. GRB 030329: all-sky CCD images by K. Shiokawa immediately after the burst
  72. GRB030501, optical observation
  73. GRB030501 observation report
  74. GRB030501 triangulation (correction to GCN 2194)
  75. GRB030329: RTT150 optical observations and upper limit for a host
  76. GRB 030429: Radio Observations
  77. GRB 030429: redshift from VLT spectroscopy
  78. GRB 030429: IR photometry with IRSF/SIRIUS
  79. GRB030501B triangulation (single error box)
  80. GRB 030329 Optical Observations
  81. GRB030328, optical observation
  82. GRB 030329, BVRI photometry
  83. GRB030429: Optical Observations
  84. GRB030501: TAROT candidate afterglow present in archival images
  85. GRB 030501: TAROT possible candidate counterpart
  86. IPN triangulation of GRB030501 (IBIS event; annulus)
  87. GRB 030429: confirmation of afterglow candidate
  88. GRB030425: CrAO optical observation
  89. IPN triangulation of GRB030428 (two large error boxes)
  90. GRB 030329 Oprical observations in Rozhen observatory
  91. GRB 030429: ROTSE-III observations
  92. GRB 030324: Radio Observations
  93. GRB030329 observed as a sudden ionospheric disturbance (SID)
  94. SNeIa AS THE POSSIBLE PROGENITORS OF SHORT-DURATION GRBs.
  95. GRB030329, SPM optical observations (Correction)
  96. GRB030329, SPM optical observations
  97. GRB 030329, the review of the sky area in plate archive (1950-1998)
  98. GRB 030329: Spectral Evolution of SN 2003dh
  99. Optical Observations of GRB 030418 with Magellan
  100. GRB 030329: optical spectropolarimetry at VLT

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