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"

27395 results found.

  1. GRB02033 NIR observation at KPNO
  2. GRB020331 field photometry
  3. GRB 020331, NIR observations
  4. GRB020331(=H1963): The "Easter" Burst Detected by HETE
  5. GRB 020322: BeppoSAX observations of the X-ray afterglow
  6. GRB011211: HST Observations of Optical Afterglow and Host Galaxy
  7. Near-Infrared Observations of GRB020322 at TIRGO
  8. GRB 020321, Radio Observations
  9. GRB 020322: Optical Observations
  10. GRB020127: Proposed Host Galaxy Detection and Identification of Afterglow
  11. GRB 020321: Optical observations
  12. GRB020317 BVRI field photometry
  13. GRB011211 revised BVRI field photometry
  14. GRB020305 BVRI field photometry
  15. GRB020322 BVRI field photometry
  16. GRB 020322: Optical Sources and Improved Astrometry
  17. GRB020317: optical observations
  18. GRB020321 optical observations
  19. GRB020321: a faint BeppoSAX detection
  20. GRB 020317 : KISO Optical Observations
  21. GRB020317 (=H1959): Localization by HETE of a Low Fluence GRB
  22. GRB 020305: Optical Observations
  23. GRB020317, optical observations
  24. GRB 020317: Optical observations
  25. GRB 011121: Third HST Epoch
  26. GRB020305: Properties of the Candidate Optical Afterglow
  27. GRB 011121: HST Observations reveal an intermediate-time multicolor
  28. GRB011130 (XRF011130) Second Epoch Chandra Observations
  29. GRB020305: Subaru Optical Observations
  30. XRF/GRB 011030: Detection of the Probable Host Galaxy
  31. GRB 020305: Candidate optical afterglow
  32. GRB020305, optical observations
  33. IPN triangulation of GRB020305 (HETE 1939)
  34. GRB020305 (=H1939): Localization of a GRB by HETE
  35. HST Imaging of the afterglow and host of GRB 011121
  36. IPN detection and localization of Cygnus X-1 flares
  37. SGR1900+14 activity
  38. IPN Upper Limits to a GRB Associated With SN2002ap
  39. GRB020124 BVRI field photometry
  40. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  41. SN2002ap (SN/GRB?) Echelle spectra
  42. GRB020127 Optical Observations
  43. SN 2002ap in M74
  44. SN2002ap (SN/GRB?) UBVRI Field Photometry
  45. GRB020127: Chandra Observations and Prospective Counterparts
  46. pre-SN2002ap (SN/GRB?) imaging of M74
  47. Type Ib/c SN2002ap (SN/GRB?) Radio Observations
  48. GRB020124, optical observations
  49. GRB 020127, I-band observations starting 3.14-hr after the event
  50. GRB010921 Optical Observations
  51. GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE
  52. GRB020124: Optical observations
  53. GRB 020124: Optical observations
  54. GRB 020124: Optical afterglow
  55. GRB020124(=H1896): Localization of a Long GRB by HETE
  56. Possible optical counterpart to a GRB
  57. GRB011212, Optical Observations
  58. Optical polarization observations for GRB011211
  59. GRB 011211: Detection of the Probable Host Galaxy
  60. GRB 011130 and GRB 011212 - Milagro GeV/TeV Observations
  61. GRB 011130: Optical Observations of X-ray and Radio Sources
  62. GRB 011212: optical observation at Asiago
  63. GRB 011211: Evidence for an Optical Break
  64. GRB 011211: TNG Spectroscopic Observations
  65. optical follow-up of GRB(XRF) 011211
  66. GRB 011212: optical observation at Oslo (relayed)
  67. GRB 011211, Optical Observations
  68. GRB011212, BVRI field photometry
  69. GRB011211, BVRI field photometry
  70. GRB011212 (=H10001): An X-Ray Rich GRB Detected by HETE
  71. Fading of the optical source associated of XRF 011211
  72. GRB 011211 Optical Observations: Likely Afterglow
  73. GRB011130 (=XRF011130): Further analysis of Chandra Target of
  74. GRB011130 (XRF011130) Chandra Observations
  75. GRB011130 (=XRF011130): Scheduled Target of Opportunity
  76. GRB 011130, K band observations
  77. GRB011130, optical observations
  78. GRB011130 (=XRF011130): Second Revised Localization by HETE
  79. GRB011130 (XRF011130) SDSS PT i-band observations
  80. XRF011130: Infrared Observations
  81. GRB 011121
  82. GRB011130 (=H1864): An X-Ray Rich GRB Detected by HETE
  83. GRB 011121: J-band observations
  84. GRB 011121: NIR observations, host galaxy?
  85. GRB011121: UBRI Observations
  86. GRB 011121 J-Band Astrometry
  87. GRB 011121: Detection of Bright IR Counterpart
  88. GRB011121: possible redshift, continued decay
  89. GRB 011030: TNG K-band observation
  90. XRF011030: J and K band observations
  91. XRF011030: Chandra Observations
  92. GRB011030: Z-band observations
  93. GRB 011030 R band observations
  94. GRB 011030 I-band Observation
  95. The X-ray Flash 011030 ('GRB 011030')
  96. Non-triggered burst 011030 ("GRB 011030")
  97. The Radio Afterglow from the X-ray Rich GRB 011030
  98. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  99. GRB 970828: HST Observations of the Host Galaxy
  100. GRB 000131: HST Detection of the Host Galaxy

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