Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! See news and announcements

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"

45651 results found.

  1. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  2. SN2002ap (SN/GRB?) Echelle spectra
  3. SN2002ap (SN/GRB?) optical spectrographic observations
  4. GRB020127, WSRT radio observations
  5. GRB020127 Optical Observations
  6. SN 2002ap (SN/GRB?)
  7. SN 2002ap in M74
  8. SN2002ap (SN/GRB?) UBVRI Field Photometry
  9. GRB020127: Chandra Observations and Prospective Counterparts
  10. pre-SN2002ap (SN/GRB?) imaging of M74
  11. SN 2002ap (hypernova / GRB ??): special list on VSNET
  12. Type Ib/c SN2002ap (SN/GRB?)
  13. Type Ib/c SN2002ap (SN/GRB?) Radio Observations
  14. GRB020124, optical observations
  15. GRB020127: Optical observations
  16. GRB 020127, I-band observations starting 3.14-hr after the event
  17. IPN detection of further activity from SGR1806-20
  18. IPN triangulation of GRB020127 (=H1902)
  19. GRB020127 Optical Observations -- Erratum to GCN 1230
  20. GRB010921 Optical Observations
  21. GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE
  22. GRB020124: Optical observations
  23. VLT observations of GRB 020124: The fading optical/near-infrared afterglow
  24. GRB020124: Optical observations
  25. GRB 020124: Optical observations
  26. GRB 020124 Optical Observations
  27. IPN triangulation of GRB020124 (HETE 1896)
  28. IPN observations of SGR1806-20
  29. GRB 020124: Optical afterglow
  30. GRB020124(=H1896): Localization of a Long GRB by HETE
  31. HETE 1896: Optical observations
  32. GRB optical counterpart candidate in GCN 1217 is M dwarf
  33. Possible optical counterpart to a GRB
  34. GRB011212, Optical Observations
  35. GRB011211: BeppoSAX/GRBM data
  36. Optical polarization observations for GRB011211
  37. GRB 011211: Detection of the Probable Host Galaxy
  38. GRB 011130 and GRB 011212 - Milagro GeV/TeV Observations
  39. Color indices of the afterglow of GRB011211
  40. GRB011212: Optical observations at Gunma
  41. GRB 011211, spectrum and optical photometry
  42. GRB 011130: Optical Observations of X-ray and Radio Sources
  43. GRB 011130, Radio/X-ray Comparison
  44. GRB011212: Optical observations
  45. GRB 011212: optical observation at Asiago
  46. GRB 011211: Evidence for an Optical Break
  47. GRB 011211: TNG Spectroscopic Observations
  48. optical follow-up of GRB(XRF) 011211
  49. GRB 011212: optical observation at Oslo (relayed)
  50. GRB 011211: Optical Spectroscopy
  51. GRB 011211, Optical Observations
  52. GRB011212, BVRI field photometry
  53. GRB011211, BVRI field photometry
  54. GRB011212: Optical observations
  55. GRB 011211: BVRi-band photometry
  56. GRB011212 (=H10001): An X-Ray Rich GRB Detected by HETE
  57. Fading of the optical source associated of XRF 011211
  58. XMM-Newton observation of GRB011211
  59. GRB 011211 Optical Observations: Likely Afterglow
  60. GRB011130 (=XRF011130): Further analysis of Chandra Target of
  61. GRB011211(=XRF011211): BeppoSAX refined positions
  62. BeppoSAX Alert: GRB011211(=XRF011211)
  63. GRB 011130: Optical Observations of Chandra Sources
  64. GRB 011130: Optical Observations of Chandra sources
  65. GRB011130 (XRF011130) Chandra Observations
  66. GRB011130 (=XRF011130): Scheduled Target of Opportunity
  67. GRB 011130: Magellan spectroscopy
  68. Sub-mm and Centimeter Detections of the Host Galaxy of GRB000418
  69. GRB011130, optical observations
  70. GRB 011130, K band observations
  71. GRB011130, optical observations
  72. GRB011130 (=XRF011130): Second Revised Localization by HETE
  73. GRB 011130 I-band Observation
  74. GRB011130 (XRF011130) optical observations
  75. GRB011130 (XRF011130) SDSS PT i-band observations
  76. XRF011130: Infrared Observations
  77. GRB011130, Radio Observations
  78. Detection of the X-ray afterglow of GRB011121 by BeppoSAX
  79. GRB011130 (=XRF011130), Optical Observations
  80. XRF011130: NEAT Optical Observations
  81. GRB011130 (=XRF011130): Revised Localization of an X-ray
  82. GRB001109, Radio Monitoring
  83. GRB 011121: Errata URL
  84. GRB 011121
  85. GRB011130 (=H1864): An X-Ray Rich GRB Detected by HETE
  86. GRB 011121: J-band observations
  87. GRB 011121: NIR observations, host galaxy?
  88. GRB010921 - Milagro GeV/TeV Observations
  89. GRB 011121: HST Scheduled
  90. GRB011121: fainter still
  91. Correction: GCN1157 (GRB 011121)
  92. GRB011121: UBRI Observations
  93. GRB011121
  94. GRB 011121: Radio Observations
  95. GRB 011121 J-Band Astrometry
  96. GRB011121: continued decay
  97. GRB 011121: Detection of Bright IR Counterpart
  98. GRB011121: possible redshift, continued decay
  99. GRB011121: fading behavior
  100. GRB011121: possible optical counterpart

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov