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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

32722 results found.

  1. GRB 240419A: VLT/UVES redshift of z = 5.178
  2. GRB 240419A: VLT optical afterglow detection
  3. EP240416a: J-band observations with WINTER
  4. EP240414a: GMG observation
  5. GRB 240418A: TSHAO Zeiss-1000 optical upper limit
  6. GRB 240418A: NOT optical upper limits
  7. GRB 240418A: AKO Upper Limit
  8. GRB 240411A: GOTO early optical upper limits
  9. Fermi GRB 240417A: Global MASTER-Net observations report
  10. LIGO/Virgo/KAGRA S240413p: X-ray upper limits from EP-WXT for the candidate AGN counterpart
  11. EP240416A: Terskol Zeiss-2000 optical upper limit
  12. EP240416A: Khureltogoot optical upper limit
  13. Improved IPN triangulation of GRB 240411A
  14. EP240416a: BOOTES-2/TELMA Optical Upper Limit
  15. EP240414a: GSP detects optical candidate counterpart AT2024gsa
  16. LIGO/Virgo/KAGRA S240413p: DECam GW-MMADS candidates
  17. EP240414a: Pan-STARRS detects re-brightening of the candidate counterpart AT2024gsa
  18. LIGO/Virgo/KAGRA S240413p: historical ATLAS and ZTF observations of the candidate AGN counterpart
  19. GRB 240415A: Glowbug gamma-ray detection
  20. GRB 240414A: Glowbug gamma-ray detection
  21. LIGO/Virgo/KAGRA S240413p: STEP - T80S Search and Candidate Counterpart Identification
  22. GRB 240415B: GECAM-B detection
  23. EP 240416a: Xinglong and NOT decaying optical counterpart
  24. GRB 240415A: Swift-BAT refined analysis
  25. EP240416A: MASTER optical observations
  26. GRB 240411A: Glowbug gamma-ray detection
  27. GRB 240414A: Swift-BAT refined analysis
  28. EP240416a: Kinder optical counterpart candidate
  29. GRB 240414A: AbAO optical upprer limit
  30. GRB 240415A: Swift/UVOT Detection
  31. EP240413a: BOOTES-2/TELMA Optical Upper Limit
  32. GRB 240415A: Fermi GBM Observation
  33. GRB 240414A: GAD Observatory, La Spezia, Italy ,upper limit
  34. GRB 240415A: Earliest optical followup with the Kinder observations
  35. GRB 240414A: GMG observation
  36. EP240414a: EP-FXT follow-up observation
  37. GRB 240415B: Swift ToO observations
  38. GRB 240415A: OHP/T193 optical observations
  39. GRB 240415A: optical afterglow detection from the INAF Asiago Observatory
  40. GRB 240415A: SAO RAS optical observations
  41. GRB 240415A: Mondy optical transient detection (photometry correction in GCN 36118 )
  42. GRB 240414A: Fermi GBM Observation
  43. Fermi GRB 240415A: Global MASTER-Net observations report
  44. GRB 240415A: Mondy optical transient detection
  45. GRB 240414A: Photometric observation from 2.2m CAHA
  46. IceCube-240412A: Upper limits from a search for additional neutrino events in IceCube
  47. GRB 240414A: Swift/UVOT Detection
  48. LXT 240402A/GRB 240402B: Swift follow-up observations
  49. GRB 240414A: Mondy optical observations
  50. GRB 240414A: AKO Optical Upper Limit
  51. X-ray transient EP 240414a - GTC spectroscopic observations
  52. GRB 240415A: Prompt Swift-XRT observations
  53. GRB 240415A: Swift detection of a burst
  54. EP240413a: Upper limits from GECAM-B Observation
  55. EP 240414a: NOT optical counterpart confirmation
  56. GRB240414A : J-band upper limits from WINTER
  57. GRB 240414A : OHP/T193 second epoch of optical follow-up and afterglow detection
  58. GRB 240414A: MarSEC Observatory, Vicenza, Italy, UPPER LIMIT
  59. LIGO/Virgo/KAGRA S240413p: No Counterparts in DDOTI/OAN Optical Observations
  60. EP240413A: GOTO optical upper limits
  61. GRB 240414A: Skynet Optical Afterglow Observations
  62. Swift GRB 240414A: Global MASTER-Net observations report
  63. EP240414a: Kinder optical counterpart candidate possibly associated with the galaxy SDSS J124601.99-094309.3
  64. IPN triangulation of GRB 240410A
  65. EP240413a: possible detection of the X-ray emission with EP-FXT after 14 hours
  66. IPN triangulation of GRB 240411A
  67. Fermi-LAT gamma-ray observations of IceCube-240412A
  68. GRB 240414A : MITSuME Akeno optical upper limits
  69. GRB 240414A: Redshift confirmation from GTC/OSIRIS+
  70. GRB 240414A : OHP/T193 redshift determination
  71. GRB 240414A : OHP/T193 optical counterpart detection
  72. LIGO/Virgo/KAGRA S240413p: Updated Sky localization
  73. LIGO/Virgo/KAGRA S240413p: Zwicky Transient Facility observations
  74. EP240408a: GSP optical upper limit
  75. GRB 240411B: CrAO/ZTSh optical observations
  76. GRB 240411B: Kinder observations with Lulin observatory
  77. LIGO/Virgo/Kagra S240413p: NED Galaxies in the Localization Volume
  78. LIGO/Virgo/KAGRA S240413p: Identification of a GW compact binary merger candidate
  79. GRB 240411B: HiPERCAM/GTC observation
  80. GRB 240411B: Swift-BAT refined analysis
  81. GRB 240411B: 1.3m DFOT Optical observations
  82. GRB 240411A: GRBAlpha detection
  83. GRB 240411B: OHP/T193 optical observations
  84. GRB 240405A: Glowbug gamma-ray detection
  85. GRB 240411B: LCO optical afterglow detection
  86. GRB 240408B: GRBAlpha detection
  87. EP240408A: MASTER optical observations
  88. EP240408a: GROND detection of a candidate counterpart
  89. EP240408a: Swift follow-up observation
  90. X-ray transient EP240315a: second epoch e-MERLIN radio observations
  91. GRB 240405A: GRBAlpha detection
  92. IceCube-240327B: GRANDMA/Kilonova-Catcher observations of 4FGL J0555.9+0030 and optical upper limits
  93. Fermi GRB 240408A: Global MASTER-Net observations report
  94. GRB 240402C: CALET Gamma-Ray Burst Monitor detection
  95. Fermi GRB 240407A: Global MASTER-Net observations report
  96. Fermi-LAT gamma-ray observations of IceCube-240327B
  97. Fermi-LAT gamma-ray observations of IceCube-240327A
  98. LXT 240402A/GRB 240402B: rest-frame energetics from Konus-Wind observation
  99. Fermi GRB 240405B: Global MASTER-Net observations report
  100. GRB 240402C: Glowbug gamma-ray detection

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