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"

7407 results found.

  1. GRB 050505 - Faulkes Telescope North observations
  2. GRB050505: Infrared observations
  3. GRB050505: AAVSO observations
  4. GRB 050505: Keck absorption spectrum and redshift (z=4.27)
  5. GRB050505: Optical Afterglow Candidate
  6. GRB 050416b:Swift XRT afterglow upper limits
  7. GRB 050416b:Swift XRT afterglow upper limits
  8. GRB050502b: Afterglow Confirmation: Correction to OT Coordinates
  9. GRB050502b: Afterglow Confirmation
  10. GRB050502A: Optical Observations
  11. Swift UVOT refined analysis
  12. GRB 050502: Confirmed variability of the afterglow candidate +
  13. GRB050502 - Correction on the Optical Candidate from the Liverpool
  14. GRB050502 - Optical Candidate from the Liverpool Telescope
  15. GRB 050421: NIR observations
  16. GRB 050416b: Tentative Swift XRT Position
  17. GRB050416: P200 NIR Observations
  18. GRB 050416: Swift XRT Position
  19. GRB 050416: Radio observations
  20. GRB050416: P60 Afterglow Candidate
  21. GRB 050412 : XingLong optical observation
  22. GRB 050408: Subaru Observations
  23. GRB 050408 Optical Observations
  24. GRB 050408: Magellan astrometry and photometry
  25. GRB 050408: First Optical observations with TFOSC at the RTT150
  26. GRB 050408 optical candidate
  27. Swift-UVOT Optical Counterpart Candidate to XRF 050406
  28. GRB 050401 Optical Observations
  29. GRB050402: XDSS counterpart
  30. GRB050401: ROTSE-III Detection of Prompt Optical Counterpart
  31. GRB 050401: Optical afterglow confirmed
  32. GRB 050401: Optical afterglow candidate
  33. GRB 050319 R band observations
  34. GRB 050319: NIR afterglow candidate
  35. GRB 050319:Near IR afterglow
  36. GRB050319: BR optical photometry
  37. GRB 050319 : Confirmation of optical afterglow decay
  38. GRB 050315, SMARTS optical afterglow decay
  39. GRB050316: MASTER optical observations
  40. GRB 050315, SMARTS optical/IR afterglow observations
  41. GRB 050315: Absorption redshift
  42. GRB 050306: Radio Observations
  43. GRB 050306: Confirmation of X-ray afterglow
  44. GRB 050309, Early optical limits from RAPTOR
  45. GRB 050306: CORRECTION to date of observation
  46. GRB 050306: R-band observations
  47. GRB 050306: No Swift UVOT Optical Counterpart Detected
  48. GRB 050306: REM optical-infrared observations
  49. GRB 050306: Possible X-ray Afterglow Position from the Swift
  50. GRB 050126: Confirmation of the NIR afterglow candidate
  51. GRB 050219b: candidate NIR afterglow
  52. GRB050215b: Faulkes North and SDSS limits on UKIRT candidate
  53. GRB 050215B: Radio Observations
  54. GRB 050215b: XRT confirmation of IR afterglow candidate
  55. GRB050215b: P60 Optical Observations
  56. GRB 050215b: Swift XRT Source Variability
  57. GRB 050215B: candidate afterglow
  58. GRB 050124: Radio Observations
  59. GRB 050126: A NIR afterglow candidate in the revised XRT error circle
  60. GRB 050126: Radio Observations
  61. GRB 050128: Swift XRT prompt afterglow position
  62. GRB 050123 : I-band follow-up observation
  63. GRB041223: decay of the afterglow
  64. GRB041223: optical and NIR observations with REM
  65. GRB 041219 : optical follow-up observations
  66. Deep RAPTOR observations during GRB 041219
  67. GRB041218: Continued P60 Optical Observations
  68. GRB 041219: Infrared Afterglow Candidate
  69. GRB 041219: Infrared Afterglow Candidate
  70. GRB 041217: PROMPT Observations
  71. GRB041218: optical observations
  72. GRB 041218; optical candidate
  73. GRB 041218: Optical observations
  74. GRB041211, Faulkes Telescope optical observation
  75. GRB041006: Fading X-ray Afterglow Observed with Chandra
  76. GRB 041006 : Optical follow-up observation at TAROT
  77. GRB041006: Fading of optical afterglow candidate
  78. GRB 041006 : Optical follow-up observation at KISO
  79. GRB 041006: Finding chart
  80. GRB 041006: Optical afterglow candidate
  81. radio observations, GRB 040924
  82. GRB040924,optical observation
  83. GRB 040924: detection of possible host galaxy by Subaru
  84. GRB040924, RTT150 optical observation
  85. GRB040924: Afterglow magnitude at t=17.5hr
  86. GRB040924 : Optical candidate observations at Lulin observatory
  87. GRB040924 : Optical candidate observations at Lulin observatory
  88. GRB 040924: Subaru NIR observation
  89. GRB040924: Optical afterglow properties
  90. IPN triangulation of GRB040924 (H3564)
  91. GRB040924 (H3564): Optical afterglow candidate
  92. XRF 040912: Radio Observations
  93. XRF 040916: Radio Observations
  94. GRB040912(=H3557): Chandra Candidate X-ray Afterglow
  95. XRF040916: continuing decay of OT
  96. TAROT Observations of GRB 040916 (HETE #3558)
  97. GRB040912(=H3557): Candidate Optical Afterglow
  98. XRF040916, optical observations
  99. XRF040916: Optical Transient Candidate by Subaru
  100. XRF040916, Ic observations

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