Skip to main content
New! BOOM Notices and Schema v7.0.0. 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"

36357 results found.

  1. GRB 020322 optical observations
  2. GRB 020322 optical observation
  3. GRB020317 : Near IR Observations from Mt Abu Observatory
  4. GRB 020322: Optical Sources and Improved Astrometry
  5. GRB020322, optical observations
  6. GRB 020322: Optical candidate
  7. GRB020322: Optical Observations
  8. GRB020322: BeppoSAX/NFI Observations
  9. Bepposax GRB020322 The second springtime BSAX GRB
  10. GRB 020321: Optical observations
  11. GRB 011121: Fourth Epoch of HST Imaging
  12. GRB020317: optical observations
  13. GRB020321 optical observations
  14. GRB020321: BeppoSAX/NFI Observations
  15. GRB020321: a faint BeppoSAX detection
  16. GRB 020317 : KISO Optical Observations
  17. BeppoSAX ALERT: GRB020321, the "Springtime Burst"
  18. GRB020317 (=H1959): Localization by HETE of a Low Fluence GRB
  19. GRB 020305: Optical Observations
  20. GRB020317, optical observations
  21. GRB 020317: Optical observations
  22. GRB 011121: Third HST Epoch
  23. GRB020305: Properties of the Candidate Optical Afterglow
  24. GRB 011121: HST Observations reveal an intermediate-time multicolor
  25. GRB011121, possible supernova association
  26. GRB011130 (XRF011130) Second Epoch Chandra Observations
  27. GRB020305: Subaru Optical Observations
  28. GRB 020305: Optical observations
  29. XRF/GRB 011030 Images
  30. XRF/GRB 011030: Detection of the Probable Host Galaxy
  31. GRB 020305: Candidate optical afterglow
  32. Type Ic SN2002bl (SN/GRB?) Radio Observations
  33. GRB020305: Optical Observations
  34. IPN triangulation of GRB020305 (HETE 1939)
  35. GRB020305 (=H1939): Localization of a GRB by HETE
  36. GRB 020305: Optical observations
  37. HST Imaging of the afterglow and host of GRB 011121
  38. GRB 010921: HST Observations
  39. IPN detection and localization of Cygnus X-1 flares
  40. GRB020127: Further VLA Observations of Possible Counterparts
  41. IPN detection of further SGR1900+14 activity
  42. SGR1900+14 activity
  43. IPN/HETE Detection of Bursts from SGR1900+14
  44. IPN Upper Limits to a GRB Associated With SN2002ap
  45. GRB020124 BVRI field photometry
  46. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  47. SN2002ap (SN/GRB?) Echelle spectra
  48. SN2002ap (SN/GRB?) optical spectrographic observations
  49. GRB020127 Optical Observations
  50. SN 2002ap (SN/GRB?)
  51. SN2002ap (SN/GRB?) UBVRI Field Photometry
  52. GRB020127: Chandra Observations and Prospective Counterparts
  53. pre-SN2002ap (SN/GRB?) imaging of M74
  54. SN 2002ap (hypernova / GRB ??): special list on VSNET
  55. Type Ib/c SN2002ap (SN/GRB?)
  56. Type Ib/c SN2002ap (SN/GRB?) Radio Observations
  57. GRB020124, optical observations
  58. GRB020127: Optical observations
  59. GRB 020127, I-band observations starting 3.14-hr after the event
  60. IPN detection of further activity from SGR1806-20
  61. IPN triangulation of GRB020127 (=H1902)
  62. GRB010921 Optical Observations
  63. GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE
  64. GRB020124: Optical observations
  65. VLT observations of GRB 020124: The fading optical/near-infrared afterglow
  66. GRB020124: Optical observations
  67. GRB 020124: Optical observations
  68. GRB 020124 Optical Observations
  69. IPN triangulation of GRB020124 (HETE 1896)
  70. IPN observations of SGR1806-20
  71. GRB 020124: Optical afterglow
  72. GRB020124(=H1896): Localization of a Long GRB by HETE
  73. GRB optical counterpart candidate in GCN 1217 is M dwarf
  74. Possible optical counterpart to a GRB
  75. GRB011212, Optical Observations
  76. GRB 011211: Detection of the Probable Host Galaxy
  77. GRB 011130 and GRB 011212 - Milagro GeV/TeV Observations
  78. GRB 011211, spectrum and optical photometry
  79. GRB 011130: Optical Observations of X-ray and Radio Sources
  80. GRB 011130, Radio/X-ray Comparison
  81. GRB 011212: optical observation at Asiago
  82. GRB 011211: Evidence for an Optical Break
  83. GRB 011211: TNG Spectroscopic Observations
  84. optical follow-up of GRB(XRF) 011211
  85. GRB 011212: optical observation at Oslo (relayed)
  86. GRB 011211: Optical Spectroscopy
  87. GRB 011211, Optical Observations
  88. GRB011212, BVRI field photometry
  89. GRB011211, BVRI field photometry
  90. GRB011212: Optical observations
  91. GRB 011211: BVRi-band photometry
  92. GRB011212 (=H10001): An X-Ray Rich GRB Detected by HETE
  93. Fading of the optical source associated of XRF 011211
  94. GRB 011211 Optical Observations: Likely Afterglow
  95. BeppoSAX Alert: GRB011211(=XRF011211)
  96. GRB 011130: Optical Observations of Chandra Sources
  97. GRB 011130: Optical Observations of Chandra sources
  98. GRB 011130: Magellan spectroscopy
  99. Sub-mm and Centimeter Detections of the Host Galaxy of GRB000418
  100. GRB011130, optical observations

Advanced

Download all Circulars as a .tar.gz archive:
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