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"

21795 results found.

  1. XRF030723(=H2777): Chandra Fading X-ray Afterglow Confirmed
  2. IPN/HETE summary of recent bursts from SGR1806-20
  3. XRF030723, BVRcIc field photometry update
  4. GRB021206 optical counterpart upper limit
  5. IPN triangulation of GRB030725 (=H2779; small error box)
  6. XRF030723 Radio Observations
  7. XRF 030723: confirmation of fading optical counterpart
  8. XRF030723(=H2777): Chandra Observations
  9. GRB030723: Upper limits from historical observations
  10. XRF030723: Palomar observations and proposed counterpart
  11. GRB030725 (=H2779): A Bright GRB Localized by HETE
  12. XRF030723, BVRcIc field photometry correction
  13. XRF030723, ROTSE-III Early Observations
  14. XRF030723, BVRcIc field photometry
  15. XRF 030723, optical observations
  16. XRF030723, optical observations
  17. Konus-Wind detection of the bursts from SGR1806-20 region
  18. SGR 1806-20, submm observations
  19. RXTE PCA Observations of SGR1806-20 Region
  20. IPN triangulation of GRB030714 (two large error boxes)
  21. IPN triangulation of GRB030715 (two large error boxes)
  22. GRBlog: Compilation of all GCN Circ. data
  23. GRB030329, optical observation in May
  24. IPN triangulation of GRB030626 (single large error box)
  25. IPN triangulation of GRB030626 (two large error boxes)
  26. GRB030329 -- RATAN-600 data in April-May
  27. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  28. IPN triangulation of GRB030606 (two alternate error boxes)
  29. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  30. IPN triangulation of GRB030605B (annulus)
  31. GRB 030528: tentative NIR counterpart
  32. GRB 030528, radio observations
  33. GRB030528(=H2724): Observations with the Chandra X-ray Observatory
  34. GRB030329, further radio observations at GMRT
  35. GRB030528, BVRI field photometry
  36. GRB030329, SPM optical observations
  37. GRB030528(=H2724): Revised SXC Localization
  38. GRB 030528 Bisei optical observation
  39. GRB030528 (H2724): A long GRB localized by HETE
  40. GRB 030528 (=H2724) Kyoto optical observation
  41. GRB030329, Optical observations
  42. GRB 030329: HST ACS Observations of the Host
  43. GRB 030329 Optical Observations
  44. GRB030329: XMM-Newton observation
  45. GRB 021004: HST observations
  46. GRB030324: Further Observations of the Candidate Optical Afterglow
  47. GRB030519B (=H2716): Peak Fluxes, Fluences, and Energy Spectrum
  48. GRB 030418: Second Epoch Optical Observations with Magellan
  49. HETE GRB030329, correction to Rc Observations in Loiano
  50. GRB 030329: Optical limit (contemporaneous imaging)
  51. IPN triangulation of GRB030509 (small errror box)
  52. IPN triangulation of GRB030509 - correction
  53. IPN triangulation of GRB030509 (single error box)
  54. GRB030329: RTT150 optical observations
  55. GRB030329, BVRI photometry
  56. GRB030429, refiend optical brightness
  57. GRB030418, BVRcIc field photometry
  58. GRB 030429: Redshift of neighbor galaxy
  59. GRB030429, BVRcIc field photometry
  60. XRF030416 (=U10897): An X-Ray Flash Localized by the HETE WXM
  61. GRB030429: RTT150 optical observations, a possible host galaxy
  62. GRB030329: RTT150 optical observations and upper limit for a host
  63. GRB030329: RTT150 optical observations and upper limit for a host
  64. GRB 030429: redshift from VLT spectroscopy
  65. GRB030501: TAROT candidate afterglow present in archival images
  66. GRB 030429: confirmation of afterglow candidate
  67. GRB030425: CrAO optical observation
  68. IPN triangulation of GRB030429 (annulus)
  69. GRB 030329 Oprical observations in Rozhen observatory
  70. GRB 030429: ROTSE-III observations
  71. GRB030329, SPM optical observations
  72. GRB 030329, the review of the sky area in plate archive (1950-1998)
  73. GRB 030329: optical spectropolarimetry at VLT
  74. IPN triangulation of GRB030422C (annulus)
  75. GRB 030329: wide-field photograph by R. Tamura 1 hr after the burst
  76. GRB030329: optical polarization
  77. IPN triangulation of GRB030422 (two large error boxes)
  78. MASTER:optical observations GRB030418
  79. MASTER:optical observations probable GRB030414
  80. ROTSE-III prompt optical detections of GRB 030418
  81. GRB030418: Kiso near infrared observations
  82. OT GRB 030329: early spectrum
  83. GRB030324: Candidate Optical Afterglow
  84. IPN triangulation of GRB030413 (small error box)
  85. GRB030329, optical position
  86. IPN triangulation of GRB030406 (small error box)
  87. IPN triangulation of GRB050403 (small error box)
  88. GRB030329: HET spectroscopic monitoring
  89. Kiso observation of the GRB030329 at April 6
  90. GRB030328, UBVRcIc field photometry
  91. GRB 030329 Optical observations
  92. GRB 030329, color evolution
  93. GRB 030329: possible color change
  94. GRB030329: Kiso B and R band observations
  95. SDSS 0.5m PT observations of GRB030329 (correction)
  96. SDSS 0.5m PT observations of GRB030329
  97. GRB030329: final R-band light curve by MASTER
  98. GRB 030329: Sub-millimeter detection
  99. GRB030329, new UBVRcIc field photometry
  100. GRB030328: Full Observation, X-ray Fading and Spectrum Measured

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