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"

36034 results found.

  1. GRB 020322, Radio observations
  2. Near-Infrared Observations of GRB020322 at TIRGO
  3. GRB 020321, Radio Observations
  4. GRB 020322: Optical Observations
  5. GRB020127: Proposed Host Galaxy Detection and Identification of Afterglow
  6. GRB 020321: Optical observations
  7. GRB020317 BVRI field photometry
  8. GRB011211 revised BVRI field photometry
  9. GRB020305 BVRI field photometry
  10. GRB020322 BVRI field photometry
  11. GRB 020322 optical observations
  12. GRB 020322 optical observation
  13. GRB020317 : Near IR Observations from Mt Abu Observatory
  14. GRB 020322: Optical Sources and Improved Astrometry
  15. GRB020322, optical observations
  16. GRB 020322: Optical candidate
  17. GRB020322: BeppoSAX/NFI Observations
  18. Bepposax GRB020322 The second springtime BSAX GRB
  19. GRB 020321: Optical observations
  20. GRB 011121: Fourth Epoch of HST Imaging
  21. GRB020317: optical observations
  22. GRB020321 optical observations
  23. GRB020321: BeppoSAX/NFI Observations
  24. GRB020321: a faint BeppoSAX detection
  25. GRB 020317 : KISO Optical Observations
  26. BeppoSAX ALERT: GRB020321, the "Springtime Burst"
  27. GRB020317 (=H1959): Localization by HETE of a Low Fluence GRB
  28. GRB 020305: Optical Observations
  29. GRB020317, optical observations
  30. GRB 020317: Optical observations
  31. GRB 011121: Third HST Epoch
  32. GRB020305: Properties of the Candidate Optical Afterglow
  33. GRB 011121: HST Observations reveal an intermediate-time multicolor
  34. GRB011121, possible supernova association
  35. GRB011130 (XRF011130) Second Epoch Chandra Observations
  36. GRB020305: Subaru Optical Observations
  37. GRB 020305: Optical observations
  38. XRF/GRB 011030 Images
  39. XRF/GRB 011030: Detection of the Probable Host Galaxy
  40. GRB 020305: Candidate optical afterglow
  41. Type Ic SN2002bl (SN/GRB?) Radio Observations
  42. GRB020305: Optical Observations
  43. IPN triangulation of GRB020305 (HETE 1939)
  44. GRB020305 (=H1939): Localization of a GRB by HETE
  45. GRB 020305: Optical observations
  46. HST Imaging of the afterglow and host of GRB 011121
  47. GRB 010921: HST Observations
  48. IPN detection and localization of Cygnus X-1 flares
  49. GRB020127: Further VLA Observations of Possible Counterparts
  50. IPN detection of further SGR1900+14 activity
  51. SGR1900+14 activity
  52. IPN/HETE Detection of Bursts from SGR1900+14
  53. IPN Upper Limits to a GRB Associated With SN2002ap
  54. GRB020124 BVRI field photometry
  55. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  56. SN2002ap (SN/GRB?) Echelle spectra
  57. SN2002ap (SN/GRB?) optical spectrographic observations
  58. GRB020127 Optical Observations
  59. SN 2002ap (SN/GRB?)
  60. SN2002ap (SN/GRB?) UBVRI Field Photometry
  61. GRB020127: Chandra Observations and Prospective Counterparts
  62. pre-SN2002ap (SN/GRB?) imaging of M74
  63. SN 2002ap (hypernova / GRB ??): special list on VSNET
  64. Type Ib/c SN2002ap (SN/GRB?)
  65. Type Ib/c SN2002ap (SN/GRB?) Radio Observations
  66. GRB020124, optical observations
  67. GRB020127: Optical observations
  68. GRB 020127, I-band observations starting 3.14-hr after the event
  69. IPN detection of further activity from SGR1806-20
  70. IPN triangulation of GRB020127 (=H1902)
  71. GRB010921 Optical Observations
  72. GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE
  73. GRB020124: Optical observations
  74. VLT observations of GRB 020124: The fading optical/near-infrared afterglow
  75. GRB020124: Optical observations
  76. GRB 020124: Optical observations
  77. GRB 020124 Optical Observations
  78. IPN triangulation of GRB020124 (HETE 1896)
  79. IPN observations of SGR1806-20
  80. GRB 020124: Optical afterglow
  81. GRB020124(=H1896): Localization of a Long GRB by HETE
  82. GRB optical counterpart candidate in GCN 1217 is M dwarf
  83. Possible optical counterpart to a GRB
  84. GRB011212, Optical Observations
  85. Optical polarization observations for GRB011211
  86. GRB 011211: Detection of the Probable Host Galaxy
  87. GRB 011130 and GRB 011212 - Milagro GeV/TeV Observations
  88. GRB 011211, spectrum and optical photometry
  89. GRB 011130: Optical Observations of X-ray and Radio Sources
  90. GRB 011130, Radio/X-ray Comparison
  91. GRB 011212: optical observation at Asiago
  92. GRB 011211: Evidence for an Optical Break
  93. GRB 011211: TNG Spectroscopic Observations
  94. optical follow-up of GRB(XRF) 011211
  95. GRB 011212: optical observation at Oslo (relayed)
  96. GRB 011211: Optical Spectroscopy
  97. GRB 011211, Optical Observations
  98. GRB011212, BVRI field photometry
  99. GRB011211, BVRI field photometry
  100. GRB011212: Optical observations

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