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"

35262 results found.

  1. GRB 050520: VLT/ULTRACAM observations
  2. Swift UVOT Observations of GRB 050520
  3. GRB 050520: Swift XRT refined analysis
  4. RBO Observations of GRB050520
  5. GRB 050520: P200 Observations
  6. GRB050520: Liverpool Telescope follow-up
  7. GRB 050520: TAROT optical limit
  8. GRB 050520: Swift XRT position
  9. GRB 050520: VLT/ULTRACAM observations
  10. GRB 050520: OSN optical observations
  11. GRB 050520: BART optical limit
  12. GRB 050520 - A long GRB detected with INTEGRAL
  13. Swift-BAT trigger 122203 is not a real GRB
  14. GRB 050504: Swift XRT afterglow candidate has faded
  15. XRF 050509c optical afterglow
  16. GRB 050509B and short GRB-SN association? (corrected)
  17. GRB 050509B and short GRB-SN association?
  18. GRB 050509B: Subaru Optical Observations
  19. GRB050502b: Early Observation
  20. GRB050509b, Bok telescope B-band imaging
  21. Refined Chandra analysis of GRB 050509b
  22. GRB050509b, SDSS pre-burst observations
  23. GRB 050509b: Keck/Chandra Cross-Correlation
  24. GRB 050509b: Keck/Chandra Cross-Correlation
  25. Chandra observation of GRB 050509b
  26. GRB 050509b: RAPTOR deep, early limits.
  27. GRB050509B: Optical/Infared observations
  28. GRB 050509b: Swift/UVOT follow-up measurements
  29. GRB 050509b Milagro GeV/TeV Observations
  30. GRB050509B: Optical observations at the Very Large Telescope
  31. GRB 050509b: No Optical Variability in XRT Error Circle
  32. GRB 050509a: Swift-BAT refined analysis
  33. GRB 050509c: ROTSE-III Optical Limits
  34. GRB 050509B: WSRT Radio Observations
  35. GRB050509c: REM NIR and Optical observations (errata corrige to GCN 3400)
  36. GRB 050505, early TAROT observation
  37. GRB050509c (=H3751): An X-Ray Flash Localized By HETE
  38. GRB 050509b: Further Analysis of Keck LRIS Images
  39. GRB050509c: REM NIR and Optical observations
  40. GRB 050509b: Physical Properties of the Candidate Host galaxy
  41. GRB 050505: SARA Observations
  42. Swift UVOT Follow-up Observations of GRB 050509B
  43. GRB 050509B, Optical Observations
  44. GRB 050509B: Swift/XRT refined analysis
  45. GRB 050509b: Optical observations
  46. GRB 050509b: Precision Astrometry
  47. GRB 050509b: Possible Optical Counterpart
  48. Keck/DEIMOS Spectrum of Possible Host Galaxy for GRB050509b
  49. GRB 050509A: Optical observations
  50. GRB 050509b: Optical Counterpart Candidate
  51. GRB 050509b: PAIRITEL and WIYN Observations
  52. GRB 050509b: Swift-BAT refined analysis of the short hard burst
  53. GRB 050509b: optical observations
  54. GRB 050509b: Swift XRT Position
  55. GRB 050509B: ROTSE-III Optical Limits
  56. GRB 050509a: Swift XRT Position
  57. Swift-BAT detection of GRB 050507
  58. GRB 050505: Keck I-band Magnitude
  59. GRB 050505: early time observations
  60. GRB 050505 - Faulkes Telescope North observations
  61. GRB 050502a: Swift XRT Upper Limit
  62. GRB 050505, simultaneous optical observation
  63. GRB 050505: Further Swift UVOT observations.
  64. GRB050505: AAVSO observations
  65. GRB050416A : 1 GHz limit from GMRT
  66. GRB 050505: Keck absorption spectrum and redshift (z=4.27)
  67. GRB 050505 UVOT
  68. GRB050505: Optical Afterglow Candidate
  69. GRB 050505: Swift XRT Position
  70. GRB 050502a: Optical Observations
  71. GRB 050416b:Swift XRT afterglow upper limits
  72. GRB 050416b:Swift XRT afterglow upper limits
  73. GRB 050504: Swift XRT position
  74. GRB050502: P200 Observations (Correction)
  75. GRB050502: P200 Observations
  76. GRB 050504 : R band observation at Lulin observatory
  77. Swift UVOT observation of GRB 050504
  78. GRB 050504, R band Observations
  79. GRB 050502b, V band Observations
  80. GRB050504: P60 Observations
  81. GRB 050504: A long GRB detected with INTEGRAL
  82. GRB (?) 050504: IR Observations, Intriguing Source
  83. GRB 050502b, Optical observations
  84. GRB050502a: P60 Observations (Correction)
  85. GRB050502a: P60 Observations
  86. Renewal of SGR 1806-20 activity
  87. GRB 050502a: RBO Observations
  88. GRB 050502A: WSRT Radio Observations
  89. GRB050502A: Optical Observations
  90. Swift UVOT refined analysis
  91. Retraction of Swift-BAT trigger 116145
  92. GRB 050502a : R band observation at Lulin observatory
  93. GRB 050502b : optical observation at Lulin observatory
  94. GRB 050502b: Swift XRT Position
  95. GRB 050502A: Redshift measurement based on Keck HIRES Observations
  96. GRB 050502: INTEGRAL results
  97. GRB050502: ANU 1m optical Observations
  98. GRB 050502: Confirmed variability of the afterglow candidate +
  99. GRB 050502: PAIRITEL IR Observations
  100. GRB050502 - Correction on the Optical Candidate from the Liverpool

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