HM Nautical Almanac Office: News

The 2018 edition of the UK Air Almanac is now available for download as of 2017 November 8th.

We are delighted to announce that we have released NavPac 4 as a free optional upgrade for existing registered NavPac 3.4 users who purchased NavPac and Compact Data 2016-2020. NavPac 4 can be used alongside NavPac 3.4, and NavPac 3.4 will continue to be supported until 2020.

We strongly recommend users take advantage of the free upgrade as it provides a much improved user interface and several new tools and features designed to make Celestial Navigation easier for the Navigator.

These include:

• new Star Chart Displays in the Find It function,
• a new feature called "Find Next" in the Sight Reduction function that calculates when and where a vessel will be for the next Sun rise/set/meridian Passage and Civil/Nautical/Astronomical Twilight based on the vessel's position, DR course and speed,
• a night mode which makes NavPac convenient to use in situations which require the user to retain their night vision.

For a full list of new features, and to obtain your copy of NavPac 4, please visit the NavPac 4 website.

A new paper by F.R. Stephenson, L.V. Morrison and C.Y. Hohenkerk, "Measurement of the Earth's rotation: 720 BC to AD 2015" in Proceedings of the Royal Society A 472 has been published presenting the most comprehensive assembly and analysis of historical data pertaining to the rotation of the Earth before the introduction of the Atomic Time scale in 1962. The paper can be downloaded from the DOI web site.

The latest version of the UK Air Almanac for 2017 is now available for download.

Information on the visibility of the new crescent moon for Ramadan and Eid al-Fitr 2016 is available for Mecca and a selection of locations across the United Kingdom for the New Moons of June 5th and July 4th.

This latest version of the UK Air Almanac for 2016 is now available for download.

This latest version of the UK Air Almanac for 2015 is now available for download.

Information on the visibility of the new crescent moon for Ramadan and Eid al-Fitr 2015 is available for Mecca and a selection of locations across the United Kingdom for the New Moons of June 16th and July 16th.

This release of HMNAO's NavPac astro-navigation software for Windows can be found in the new edition of NavPac and Compact Data 2016-2020 due out at the end of March 2015. Please consult the NavPac page for further information.

An updated version of Websurf is available for testing. The interface has been completely revised with the intention of making it more user friendly. We would welcome any feedback on the improvements we have made.

Information on the visibility of the new crescent moon for Ramadan and Eid al-Fitr is available for Mecca and a selection of locations across the United Kingdom for the New Moons of July 8th and August 8th. Our new style of global crescent moon visibility maps are also provided.

The NavPac Status page was updated on March 11th 2013 to include a procedure for downloading a corrected star magnitudes file STARS3.dat.

The revised third edition of this reference publication is available from University Science Books.

Visibility of the new crescent Moon and twilight information are provided for those visiting the Olympic Park in the period July 21st through to August 12th.

An update (v3.1.9) to the release version of Navpac (v3.1.6) is available as of 2011 December 6th to registered users. Please consult the NavPac page for further information.

This publication has been made available as a free pdf download on 2011 September 20th.

It has been confirmed that the Queen's Official Birthday will be held on 2012 June 16th and not 2012 June 9th as stated on our Astronomical and Calendarial Data Sheet for 2012 (Astronomical Information Sheet No.96). The original date of The Queen's Official Birthday nominally falls on the second Saturday of June. However, this date is subject to confirmation and in this case has been moved to the third Saturday of June.

On November 23rd 2010, it was announced (Hansard Vol. 519, No.77, p.142) that a public holiday will occur on April 29th, 2011 on the occasion of the marriage of HRH Prince William and Ms. Catherine Middleton. These arrangements have been confirmed for England, Wales and Scotland and it is expected that they will also apply to Northern Ireland.

An update (v3.1.8) to the release version of Navpac (v3.1.6) is available as of 2010 June 15th to registered users. Please consult the NavPac page for further information.

On January 5th 2010, a statement on the Queen's Diamond Jubilee was made by the Secretary of State for Business, Innovation and Skills. It stated that the late May Bank Holiday on Monday May 28th 2012 will be moved forwards by one week to Monday June 4th 2012 and that Tuesday June 5th 2012 is to be declared a one-off bank holiday thus creating a four day break to celebrate the Queen's Diamond Jubilee. Although the announcement covers England and Wales, it is expected that these changes will also apply to Scotland and Northern Ireland.

A job vacancy exists within HMNAO for a Mathematician / Astronomer. For more information and where to apply, please download the job outline. The closing date for applications is July 17th 2009.

For users of HMNAO's Astronomical & Calendarial sheets, there is an addendum to the sheets for 2007 to 2012 inclusive in regard to the St. Andrew's Day Holiday introduced by the Scottish Executive earlier this year.

We would like to remind potential observers that our project to observe the new crescent moon is still running. We have experienced some difficulties with the e-mail system for advising observers of the date of the next new moon recently. The problem has now been resolved and we hope you will continue to make observations of the new crescent moon. We wish to apologise to our observers for these difficulties.

HMNAO will be moving part of its infrastructure to the UK Hydrographic Office in Taunton at the beginning of December. If you wish to order data or discuss your requirements, please use the Taunton contact address and telephone numbers. E-mail should be forwarded to our new e-mail addresses automatically.