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"

26042 results found.

  1. GRB020813: optical observations; possible host galaxy
  2. GRB 020813, radio detection
  3. GRB 020812 : optical afterglow candidate
  4. GRB020812: optical observations
  5. GRB020813, optical observations
  6. GRB020812: possible afterglow candidate
  7. GRB020812: possible afterglow candidate
  8. GRB020813, astrometric position
  9. Spectropolarimetry of GRB 020813
  10. GRB 020813 Afterglow Observations; Possible break
  11. GRB 020813: Absorption redshift
  12. GRB020813: optical afterglow
  13. GRB020813: Candidate Optical Afterglow
  14. GRB 020715, optical observations
  15. GRB 020714, optical observations
  16. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  17. HST Imaging of the Host of GRB 011121
  18. GRB020801, optical afterglow candidate
  19. GRB020331: Late-time Optical Light Curve (re-submission)
  20. GRB020331: Late-time Optical Light Curve
  21. GRB 020405: HST observations reveal red bump
  22. GRB 020410: Discovery of Probable OT by HST
  23. GRB 020124, HST observations of the fading afterglow
  24. GRB 020705: Optical observations
  25. GRB 020625: Optical observations
  26. GRB 020531: optical photometry of Chandra sources
  27. HETE #2081: Optical observations
  28. GRB/XRF 020427, detection of an underlying system with the VLT
  29. GRB 020531, simultaneous optical observations
  30. GRB 020604, optical observations
  31. GRB 020531/Candidate Redshift
  32. GRB 020418, optical/near-IR observations
  33. GRB020531: Upper Limit for Detection of Two TAROT Sources
  34. GRB 020603: Optical observations
  35. XRF020427: Chandra Identification of a Likely X-ray Counterpart
  36. XRF020427: Chandra Observations and Candidate X-ray Counterparts
  37. GRB(XRF) 020427: X-ray afterglow with BeppoSAX
  38. GRB020321 : Optical observations.
  39. GRB020331: Third Epoch and Revised Second Epoch Optical
  40. GRB 020418: Optical observations
  41. GRB 020124: Optical observations
  42. GRB 020418: Optical observations
  43. GRB020410: BeppoSAX NFI observations refined analysis
  44. GRB020405: predicted break
  45. GRB 020409: Optical observations
  46. GRB 020409: No Evidence for an Optical Afterglow
  47. GRB 020409, 2nd epoch optical observations
  48. GRB 020331 Kyoto observation on March 31
  49. GRB 020409
  50. GRB020406(?), optical observations
  51. X-ray afterglow of GRB020321
  52. GRB020331: Confirmation of Afterglow Candidate with Magellan
  53. GRB 020405: Moderate-resolution spectroscopy
  54. GRB020331: Optical Observations of Afterglow Candidate
  55. Revised Photometry of the Optical Afterglow of GRB 020405
  56. GRB 020331: Candidate Optical Afterglow
  57. GRB 020405: Decay index
  58. GRB020405, Radio Observations
  59. GRB020405: VLT spectroscopy
  60. Fading Optical Afterglow and Possible Host Galaxy of GRB 020405
  61. GRB 020405: Optical afterglow candidate
  62. GRB 020331: NIR Observations
  63. GRB 020331: NIR Observations
  64. GRB020331 NIR observation at KPNO (re-submission)
  65. GRB02033 NIR observation at KPNO
  66. GRB020331 field photometry
  67. GRB 020331, NIR observations
  68. GRB 020331: Optical observations
  69. GRB 020322: BeppoSAX observations of the X-ray afterglow
  70. GRB011211: HST Observations of Optical Afterglow and Host Galaxy
  71. GRB 020322, Radio observations
  72. Near-Infrared Observations of GRB020322 at TIRGO
  73. GRB 020321, Radio Observations
  74. GRB 020322: Optical Observations
  75. GRB020127: Proposed Host Galaxy Detection and Identification of Afterglow
  76. GRB 020321: Optical observations
  77. GRB020317 BVRI field photometry
  78. GRB 020322 optical observations
  79. GRB020322: Candidate Optical Afterglow
  80. GRB020322, optical observations
  81. GRB 020322: Optical candidate
  82. GRB 020321: Optical observations
  83. GRB 011121: Fourth Epoch of HST Imaging
  84. GRB020305: NIR observations
  85. GRB 020305: Optical Observations
  86. GRB 020317: Optical observations
  87. GRB 011121: Third HST Epoch
  88. GRB020305: Properties of the Candidate Optical Afterglow
  89. GRB 011121: HST Observations reveal an intermediate-time multicolor
  90. GRB011121, possible supernova association
  91. GRB020305: Subaru Optical Observations
  92. GRB 020305: Optical observations
  93. GRB 020305: Candidate optical afterglow
  94. HST Imaging of the afterglow and host of GRB 011121
  95. GRB 010921: HST Observations
  96. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  97. VLT observations of GRB 020124: The fading optical/near-infrared afterglow
  98. GRB 020124 Optical Observations
  99. GRB 020124: Optical afterglow
  100. GRB 011211: Detection of the Probable Host Galaxy

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