Skip to main content
Circulars over Kafka event name backfill. 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"

24602 results found.

  1. GRB 020405: Decay index
  2. Short RXTE/ASM transient 020406; may be a GRB
  3. GRB020405, Radio Observations
  4. GRB 020405, U-band observations
  5. GRB011212: Optical Observations
  6. GRB 020331: NIR Observations
  7. GRB020331 NIR observation at KPNO (re-submission)
  8. GRB02033 NIR observation at KPNO
  9. GRB020331 field photometry
  10. GRB 020331, NIR observations
  11. GRB020331(=H1963): The "Easter" Burst Detected by HETE
  12. GRB 020322: BeppoSAX observations of the X-ray afterglow
  13. GRB011211: HST Observations of Optical Afterglow and Host Galaxy
  14. Near-Infrared Observations of GRB020322 at TIRGO
  15. GRB 020321, Radio Observations
  16. GRB 020322: Optical Observations
  17. GRB020127: Proposed Host Galaxy Detection and Identification of Afterglow
  18. GRB 020321: Optical observations
  19. GRB020317 BVRI field photometry
  20. GRB011211 revised BVRI field photometry
  21. GRB020305 BVRI field photometry
  22. GRB020322 BVRI field photometry
  23. GRB 020322: Optical Sources and Improved Astrometry
  24. GRB020317: optical observations
  25. GRB020321 optical observations
  26. GRB020321: a faint BeppoSAX detection
  27. GRB 020317 : KISO Optical Observations
  28. GRB020317 (=H1959): Localization by HETE of a Low Fluence GRB
  29. GRB 020305: Optical Observations
  30. GRB020317, optical observations
  31. GRB 020317: Optical observations
  32. GRB 011121: Third HST Epoch
  33. GRB020305: Properties of the Candidate Optical Afterglow
  34. GRB 011121: HST Observations reveal an intermediate-time multicolor
  35. GRB011130 (XRF011130) Second Epoch Chandra Observations
  36. GRB020305: Subaru Optical Observations
  37. XRF/GRB 011030: Detection of the Probable Host Galaxy
  38. GRB 020305: Candidate optical afterglow
  39. GRB020305, optical observations
  40. IPN triangulation of GRB020305 (HETE 1939)
  41. GRB020305 (=H1939): Localization of a GRB by HETE
  42. HST Imaging of the afterglow and host of GRB 011121
  43. IPN detection and localization of Cygnus X-1 flares
  44. SGR1900+14 activity
  45. IPN Upper Limits to a GRB Associated With SN2002ap
  46. GRB020124 BVRI field photometry
  47. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  48. SN2002ap (SN/GRB?) Echelle spectra
  49. GRB020127 Optical Observations
  50. SN 2002ap in M74
  51. SN2002ap (SN/GRB?) UBVRI Field Photometry
  52. GRB020127: Chandra Observations and Prospective Counterparts
  53. pre-SN2002ap (SN/GRB?) imaging of M74
  54. Type Ib/c SN2002ap (SN/GRB?) Radio Observations
  55. GRB020124, optical observations
  56. GRB 020127, I-band observations starting 3.14-hr after the event
  57. GRB010921 Optical Observations
  58. GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE
  59. GRB020124: Optical observations
  60. GRB 020124: Optical observations
  61. GRB 020124: Optical afterglow
  62. GRB020124(=H1896): Localization of a Long GRB by HETE
  63. Possible optical counterpart to a GRB
  64. GRB011212, Optical Observations
  65. Optical polarization observations for GRB011211
  66. GRB 011211: Detection of the Probable Host Galaxy
  67. GRB 011130 and GRB 011212 - Milagro GeV/TeV Observations
  68. GRB 011130: Optical Observations of X-ray and Radio Sources
  69. GRB 011212: optical observation at Asiago
  70. GRB 011211: Evidence for an Optical Break
  71. GRB 011211: TNG Spectroscopic Observations
  72. optical follow-up of GRB(XRF) 011211
  73. GRB 011212: optical observation at Oslo (relayed)
  74. GRB 011211, Optical Observations
  75. GRB011212, BVRI field photometry
  76. GRB011211, BVRI field photometry
  77. GRB011212 (=H10001): An X-Ray Rich GRB Detected by HETE
  78. Fading of the optical source associated of XRF 011211
  79. GRB 011211 Optical Observations: Likely Afterglow
  80. GRB011130 (=XRF011130): Further analysis of Chandra Target of
  81. GRB011130 (XRF011130) Chandra Observations
  82. GRB011130 (=XRF011130): Scheduled Target of Opportunity
  83. GRB 011130, K band observations
  84. GRB011130, optical observations
  85. GRB011130 (=XRF011130): Second Revised Localization by HETE
  86. GRB011130 (XRF011130) SDSS PT i-band observations
  87. XRF011130: Infrared Observations
  88. GRB 011121
  89. GRB011130 (=H1864): An X-Ray Rich GRB Detected by HETE
  90. GRB 011121: J-band observations
  91. GRB 011121: NIR observations, host galaxy?
  92. GRB011121: UBRI Observations
  93. GRB 011121 J-Band Astrometry
  94. GRB 011121: Detection of Bright IR Counterpart
  95. GRB011121: possible redshift, continued decay
  96. GRB 011030: TNG K-band observation
  97. XRF011030: J and K band observations
  98. XRF011030: Chandra Observations
  99. GRB011030: Z-band observations
  100. GRB 011030 R band 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